Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * linux/fs/block_dev.c |
| 3 | * |
| 4 | * Copyright (C) 1991, 1992 Linus Torvalds |
| 5 | * Copyright (C) 2001 Andrea Arcangeli <andrea@suse.de> SuSE |
| 6 | */ |
| 7 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 8 | #include <linux/init.h> |
| 9 | #include <linux/mm.h> |
| 10 | #include <linux/fcntl.h> |
| 11 | #include <linux/slab.h> |
| 12 | #include <linux/kmod.h> |
| 13 | #include <linux/major.h> |
Pavel Emelyanov | 7db9cfd | 2008-06-05 22:46:27 -0700 | [diff] [blame] | 14 | #include <linux/device_cgroup.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 15 | #include <linux/highmem.h> |
| 16 | #include <linux/blkdev.h> |
| 17 | #include <linux/module.h> |
| 18 | #include <linux/blkpg.h> |
| 19 | #include <linux/buffer_head.h> |
Nick Piggin | 585d3bc | 2009-02-25 10:44:19 +0100 | [diff] [blame] | 20 | #include <linux/pagevec.h> |
David Howells | 811d736 | 2006-08-29 19:06:09 +0100 | [diff] [blame] | 21 | #include <linux/writeback.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 22 | #include <linux/mpage.h> |
| 23 | #include <linux/mount.h> |
| 24 | #include <linux/uio.h> |
| 25 | #include <linux/namei.h> |
Vignesh Babu BM | 1368c4f | 2007-05-08 00:24:32 -0700 | [diff] [blame] | 26 | #include <linux/log2.h> |
Catalin Marinas | 2e1483c | 2009-06-11 13:24:13 +0100 | [diff] [blame] | 27 | #include <linux/kmemleak.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 28 | #include <asm/uaccess.h> |
David Howells | 07f3f05 | 2006-09-30 20:52:18 +0200 | [diff] [blame] | 29 | #include "internal.h" |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 30 | |
| 31 | struct bdev_inode { |
| 32 | struct block_device bdev; |
| 33 | struct inode vfs_inode; |
| 34 | }; |
| 35 | |
Adrian Bunk | 4c54ac6 | 2008-02-18 13:48:31 +0100 | [diff] [blame] | 36 | static const struct address_space_operations def_blk_aops; |
| 37 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 38 | static inline struct bdev_inode *BDEV_I(struct inode *inode) |
| 39 | { |
| 40 | return container_of(inode, struct bdev_inode, vfs_inode); |
| 41 | } |
| 42 | |
| 43 | inline struct block_device *I_BDEV(struct inode *inode) |
| 44 | { |
| 45 | return &BDEV_I(inode)->bdev; |
| 46 | } |
| 47 | |
| 48 | EXPORT_SYMBOL(I_BDEV); |
| 49 | |
Dave Chinner | a5491e0 | 2010-10-21 11:49:26 +1100 | [diff] [blame] | 50 | /* |
| 51 | * move the inode from it's current bdi to the a new bdi. if the inode is dirty |
| 52 | * we need to move it onto the dirty list of @dst so that the inode is always |
| 53 | * on the right list. |
| 54 | */ |
| 55 | static void bdev_inode_switch_bdi(struct inode *inode, |
| 56 | struct backing_dev_info *dst) |
| 57 | { |
Dave Chinner | a66979a | 2011-03-22 22:23:41 +1100 | [diff] [blame] | 58 | spin_lock(&inode_wb_list_lock); |
Dave Chinner | 250df6e | 2011-03-22 22:23:36 +1100 | [diff] [blame] | 59 | spin_lock(&inode->i_lock); |
Dave Chinner | a5491e0 | 2010-10-21 11:49:26 +1100 | [diff] [blame] | 60 | inode->i_data.backing_dev_info = dst; |
| 61 | if (inode->i_state & I_DIRTY) |
Nick Piggin | 7ccf19a | 2010-10-21 11:49:30 +1100 | [diff] [blame] | 62 | list_move(&inode->i_wb_list, &dst->wb.b_dirty); |
Dave Chinner | 250df6e | 2011-03-22 22:23:36 +1100 | [diff] [blame] | 63 | spin_unlock(&inode->i_lock); |
Dave Chinner | a66979a | 2011-03-22 22:23:41 +1100 | [diff] [blame] | 64 | spin_unlock(&inode_wb_list_lock); |
Dave Chinner | a5491e0 | 2010-10-21 11:49:26 +1100 | [diff] [blame] | 65 | } |
| 66 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 67 | static sector_t max_block(struct block_device *bdev) |
| 68 | { |
| 69 | sector_t retval = ~((sector_t)0); |
| 70 | loff_t sz = i_size_read(bdev->bd_inode); |
| 71 | |
| 72 | if (sz) { |
| 73 | unsigned int size = block_size(bdev); |
| 74 | unsigned int sizebits = blksize_bits(size); |
| 75 | retval = (sz >> sizebits); |
| 76 | } |
| 77 | return retval; |
| 78 | } |
| 79 | |
Peter Zijlstra | f9a1439 | 2007-05-06 14:49:55 -0700 | [diff] [blame] | 80 | /* Kill _all_ buffers and pagecache , dirty or not.. */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 81 | static void kill_bdev(struct block_device *bdev) |
| 82 | { |
Peter Zijlstra | f9a1439 | 2007-05-06 14:49:55 -0700 | [diff] [blame] | 83 | if (bdev->bd_inode->i_mapping->nrpages == 0) |
| 84 | return; |
| 85 | invalidate_bh_lrus(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 86 | truncate_inode_pages(bdev->bd_inode->i_mapping, 0); |
| 87 | } |
| 88 | |
| 89 | int set_blocksize(struct block_device *bdev, int size) |
| 90 | { |
| 91 | /* Size must be a power of two, and between 512 and PAGE_SIZE */ |
Vignesh Babu BM | 1368c4f | 2007-05-08 00:24:32 -0700 | [diff] [blame] | 92 | if (size > PAGE_SIZE || size < 512 || !is_power_of_2(size)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 93 | return -EINVAL; |
| 94 | |
| 95 | /* Size cannot be smaller than the size supported by the device */ |
Martin K. Petersen | e1defc4 | 2009-05-22 17:17:49 -0400 | [diff] [blame] | 96 | if (size < bdev_logical_block_size(bdev)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 97 | return -EINVAL; |
| 98 | |
| 99 | /* Don't change the size if it is same as current */ |
| 100 | if (bdev->bd_block_size != size) { |
| 101 | sync_blockdev(bdev); |
| 102 | bdev->bd_block_size = size; |
| 103 | bdev->bd_inode->i_blkbits = blksize_bits(size); |
| 104 | kill_bdev(bdev); |
| 105 | } |
| 106 | return 0; |
| 107 | } |
| 108 | |
| 109 | EXPORT_SYMBOL(set_blocksize); |
| 110 | |
| 111 | int sb_set_blocksize(struct super_block *sb, int size) |
| 112 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 113 | if (set_blocksize(sb->s_bdev, size)) |
| 114 | return 0; |
| 115 | /* If we get here, we know size is power of two |
| 116 | * and it's value is between 512 and PAGE_SIZE */ |
| 117 | sb->s_blocksize = size; |
Coywolf Qi Hunt | 38885bd | 2006-03-24 03:18:05 -0800 | [diff] [blame] | 118 | sb->s_blocksize_bits = blksize_bits(size); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 119 | return sb->s_blocksize; |
| 120 | } |
| 121 | |
| 122 | EXPORT_SYMBOL(sb_set_blocksize); |
| 123 | |
| 124 | int sb_min_blocksize(struct super_block *sb, int size) |
| 125 | { |
Martin K. Petersen | e1defc4 | 2009-05-22 17:17:49 -0400 | [diff] [blame] | 126 | int minsize = bdev_logical_block_size(sb->s_bdev); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 127 | if (size < minsize) |
| 128 | size = minsize; |
| 129 | return sb_set_blocksize(sb, size); |
| 130 | } |
| 131 | |
| 132 | EXPORT_SYMBOL(sb_min_blocksize); |
| 133 | |
| 134 | static int |
| 135 | blkdev_get_block(struct inode *inode, sector_t iblock, |
| 136 | struct buffer_head *bh, int create) |
| 137 | { |
| 138 | if (iblock >= max_block(I_BDEV(inode))) { |
| 139 | if (create) |
| 140 | return -EIO; |
| 141 | |
| 142 | /* |
| 143 | * for reads, we're just trying to fill a partial page. |
| 144 | * return a hole, they will have to call get_block again |
| 145 | * before they can fill it, and they will get -EIO at that |
| 146 | * time |
| 147 | */ |
| 148 | return 0; |
| 149 | } |
| 150 | bh->b_bdev = I_BDEV(inode); |
| 151 | bh->b_blocknr = iblock; |
| 152 | set_buffer_mapped(bh); |
| 153 | return 0; |
| 154 | } |
| 155 | |
Andrew Morton | b2e895d | 2007-02-03 01:14:01 -0800 | [diff] [blame] | 156 | static int |
| 157 | blkdev_get_blocks(struct inode *inode, sector_t iblock, |
| 158 | struct buffer_head *bh, int create) |
| 159 | { |
| 160 | sector_t end_block = max_block(I_BDEV(inode)); |
| 161 | unsigned long max_blocks = bh->b_size >> inode->i_blkbits; |
| 162 | |
| 163 | if ((iblock + max_blocks) > end_block) { |
| 164 | max_blocks = end_block - iblock; |
| 165 | if ((long)max_blocks <= 0) { |
| 166 | if (create) |
| 167 | return -EIO; /* write fully beyond EOF */ |
| 168 | /* |
| 169 | * It is a read which is fully beyond EOF. We return |
| 170 | * a !buffer_mapped buffer |
| 171 | */ |
| 172 | max_blocks = 0; |
| 173 | } |
| 174 | } |
| 175 | |
| 176 | bh->b_bdev = I_BDEV(inode); |
| 177 | bh->b_blocknr = iblock; |
| 178 | bh->b_size = max_blocks << inode->i_blkbits; |
| 179 | if (max_blocks) |
| 180 | set_buffer_mapped(bh); |
| 181 | return 0; |
| 182 | } |
| 183 | |
| 184 | static ssize_t |
| 185 | blkdev_direct_IO(int rw, struct kiocb *iocb, const struct iovec *iov, |
| 186 | loff_t offset, unsigned long nr_segs) |
| 187 | { |
| 188 | struct file *file = iocb->ki_filp; |
| 189 | struct inode *inode = file->f_mapping->host; |
| 190 | |
Christoph Hellwig | eafdc7d | 2010-06-04 11:29:53 +0200 | [diff] [blame] | 191 | return __blockdev_direct_IO(rw, iocb, inode, I_BDEV(inode), iov, offset, |
| 192 | nr_segs, blkdev_get_blocks, NULL, NULL, 0); |
Andrew Morton | b2e895d | 2007-02-03 01:14:01 -0800 | [diff] [blame] | 193 | } |
| 194 | |
Jan Kara | 5cee581 | 2009-04-27 16:43:51 +0200 | [diff] [blame] | 195 | int __sync_blockdev(struct block_device *bdev, int wait) |
| 196 | { |
| 197 | if (!bdev) |
| 198 | return 0; |
| 199 | if (!wait) |
| 200 | return filemap_flush(bdev->bd_inode->i_mapping); |
| 201 | return filemap_write_and_wait(bdev->bd_inode->i_mapping); |
| 202 | } |
| 203 | |
Nick Piggin | 585d3bc | 2009-02-25 10:44:19 +0100 | [diff] [blame] | 204 | /* |
| 205 | * Write out and wait upon all the dirty data associated with a block |
| 206 | * device via its mapping. Does not take the superblock lock. |
| 207 | */ |
| 208 | int sync_blockdev(struct block_device *bdev) |
| 209 | { |
Jan Kara | 5cee581 | 2009-04-27 16:43:51 +0200 | [diff] [blame] | 210 | return __sync_blockdev(bdev, 1); |
Nick Piggin | 585d3bc | 2009-02-25 10:44:19 +0100 | [diff] [blame] | 211 | } |
| 212 | EXPORT_SYMBOL(sync_blockdev); |
| 213 | |
| 214 | /* |
| 215 | * Write out and wait upon all dirty data associated with this |
| 216 | * device. Filesystem data as well as the underlying block |
| 217 | * device. Takes the superblock lock. |
| 218 | */ |
| 219 | int fsync_bdev(struct block_device *bdev) |
| 220 | { |
| 221 | struct super_block *sb = get_super(bdev); |
| 222 | if (sb) { |
Jan Kara | 60b0680 | 2009-04-27 16:43:53 +0200 | [diff] [blame] | 223 | int res = sync_filesystem(sb); |
Nick Piggin | 585d3bc | 2009-02-25 10:44:19 +0100 | [diff] [blame] | 224 | drop_super(sb); |
| 225 | return res; |
| 226 | } |
| 227 | return sync_blockdev(bdev); |
| 228 | } |
Al Viro | 47e4491 | 2009-04-01 07:07:16 -0400 | [diff] [blame] | 229 | EXPORT_SYMBOL(fsync_bdev); |
Nick Piggin | 585d3bc | 2009-02-25 10:44:19 +0100 | [diff] [blame] | 230 | |
| 231 | /** |
| 232 | * freeze_bdev -- lock a filesystem and force it into a consistent state |
| 233 | * @bdev: blockdevice to lock |
| 234 | * |
Nick Piggin | 585d3bc | 2009-02-25 10:44:19 +0100 | [diff] [blame] | 235 | * If a superblock is found on this device, we take the s_umount semaphore |
| 236 | * on it to make sure nobody unmounts until the snapshot creation is done. |
| 237 | * The reference counter (bd_fsfreeze_count) guarantees that only the last |
| 238 | * unfreeze process can unfreeze the frozen filesystem actually when multiple |
| 239 | * freeze requests arrive simultaneously. It counts up in freeze_bdev() and |
| 240 | * count down in thaw_bdev(). When it becomes 0, thaw_bdev() will unfreeze |
| 241 | * actually. |
| 242 | */ |
| 243 | struct super_block *freeze_bdev(struct block_device *bdev) |
| 244 | { |
| 245 | struct super_block *sb; |
| 246 | int error = 0; |
| 247 | |
| 248 | mutex_lock(&bdev->bd_fsfreeze_mutex); |
Christoph Hellwig | 4504230 | 2009-08-03 23:28:35 +0200 | [diff] [blame] | 249 | if (++bdev->bd_fsfreeze_count > 1) { |
| 250 | /* |
| 251 | * We don't even need to grab a reference - the first call |
| 252 | * to freeze_bdev grab an active reference and only the last |
| 253 | * thaw_bdev drops it. |
| 254 | */ |
Nick Piggin | 585d3bc | 2009-02-25 10:44:19 +0100 | [diff] [blame] | 255 | sb = get_super(bdev); |
Christoph Hellwig | 4504230 | 2009-08-03 23:28:35 +0200 | [diff] [blame] | 256 | drop_super(sb); |
Nick Piggin | 585d3bc | 2009-02-25 10:44:19 +0100 | [diff] [blame] | 257 | mutex_unlock(&bdev->bd_fsfreeze_mutex); |
| 258 | return sb; |
| 259 | } |
Nick Piggin | 585d3bc | 2009-02-25 10:44:19 +0100 | [diff] [blame] | 260 | |
Christoph Hellwig | 4504230 | 2009-08-03 23:28:35 +0200 | [diff] [blame] | 261 | sb = get_active_super(bdev); |
| 262 | if (!sb) |
| 263 | goto out; |
Josef Bacik | 18e9e51 | 2010-03-23 10:34:56 -0400 | [diff] [blame] | 264 | error = freeze_super(sb); |
| 265 | if (error) { |
| 266 | deactivate_super(sb); |
| 267 | bdev->bd_fsfreeze_count--; |
Christoph Hellwig | 4504230 | 2009-08-03 23:28:35 +0200 | [diff] [blame] | 268 | mutex_unlock(&bdev->bd_fsfreeze_mutex); |
Josef Bacik | 18e9e51 | 2010-03-23 10:34:56 -0400 | [diff] [blame] | 269 | return ERR_PTR(error); |
Nick Piggin | 585d3bc | 2009-02-25 10:44:19 +0100 | [diff] [blame] | 270 | } |
Josef Bacik | 18e9e51 | 2010-03-23 10:34:56 -0400 | [diff] [blame] | 271 | deactivate_super(sb); |
Christoph Hellwig | 4504230 | 2009-08-03 23:28:35 +0200 | [diff] [blame] | 272 | out: |
Nick Piggin | 585d3bc | 2009-02-25 10:44:19 +0100 | [diff] [blame] | 273 | sync_blockdev(bdev); |
| 274 | mutex_unlock(&bdev->bd_fsfreeze_mutex); |
Christoph Hellwig | 4fadd7b | 2009-08-03 23:28:06 +0200 | [diff] [blame] | 275 | return sb; /* thaw_bdev releases s->s_umount */ |
Nick Piggin | 585d3bc | 2009-02-25 10:44:19 +0100 | [diff] [blame] | 276 | } |
| 277 | EXPORT_SYMBOL(freeze_bdev); |
| 278 | |
| 279 | /** |
| 280 | * thaw_bdev -- unlock filesystem |
| 281 | * @bdev: blockdevice to unlock |
| 282 | * @sb: associated superblock |
| 283 | * |
| 284 | * Unlocks the filesystem and marks it writeable again after freeze_bdev(). |
| 285 | */ |
| 286 | int thaw_bdev(struct block_device *bdev, struct super_block *sb) |
| 287 | { |
Christoph Hellwig | 4504230 | 2009-08-03 23:28:35 +0200 | [diff] [blame] | 288 | int error = -EINVAL; |
Nick Piggin | 585d3bc | 2009-02-25 10:44:19 +0100 | [diff] [blame] | 289 | |
| 290 | mutex_lock(&bdev->bd_fsfreeze_mutex); |
Christoph Hellwig | 4504230 | 2009-08-03 23:28:35 +0200 | [diff] [blame] | 291 | if (!bdev->bd_fsfreeze_count) |
Josef Bacik | 18e9e51 | 2010-03-23 10:34:56 -0400 | [diff] [blame] | 292 | goto out; |
Nick Piggin | 585d3bc | 2009-02-25 10:44:19 +0100 | [diff] [blame] | 293 | |
Christoph Hellwig | 4504230 | 2009-08-03 23:28:35 +0200 | [diff] [blame] | 294 | error = 0; |
| 295 | if (--bdev->bd_fsfreeze_count > 0) |
Josef Bacik | 18e9e51 | 2010-03-23 10:34:56 -0400 | [diff] [blame] | 296 | goto out; |
Nick Piggin | 585d3bc | 2009-02-25 10:44:19 +0100 | [diff] [blame] | 297 | |
Christoph Hellwig | 4504230 | 2009-08-03 23:28:35 +0200 | [diff] [blame] | 298 | if (!sb) |
Josef Bacik | 18e9e51 | 2010-03-23 10:34:56 -0400 | [diff] [blame] | 299 | goto out; |
Christoph Hellwig | 4504230 | 2009-08-03 23:28:35 +0200 | [diff] [blame] | 300 | |
Josef Bacik | 18e9e51 | 2010-03-23 10:34:56 -0400 | [diff] [blame] | 301 | error = thaw_super(sb); |
| 302 | if (error) { |
| 303 | bdev->bd_fsfreeze_count++; |
| 304 | mutex_unlock(&bdev->bd_fsfreeze_mutex); |
| 305 | return error; |
Nick Piggin | 585d3bc | 2009-02-25 10:44:19 +0100 | [diff] [blame] | 306 | } |
Josef Bacik | 18e9e51 | 2010-03-23 10:34:56 -0400 | [diff] [blame] | 307 | out: |
Nick Piggin | 585d3bc | 2009-02-25 10:44:19 +0100 | [diff] [blame] | 308 | mutex_unlock(&bdev->bd_fsfreeze_mutex); |
| 309 | return 0; |
| 310 | } |
| 311 | EXPORT_SYMBOL(thaw_bdev); |
| 312 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 313 | static int blkdev_writepage(struct page *page, struct writeback_control *wbc) |
| 314 | { |
| 315 | return block_write_full_page(page, blkdev_get_block, wbc); |
| 316 | } |
| 317 | |
| 318 | static int blkdev_readpage(struct file * file, struct page * page) |
| 319 | { |
| 320 | return block_read_full_page(page, blkdev_get_block); |
| 321 | } |
| 322 | |
Nick Piggin | 6272b5a | 2007-10-16 01:25:04 -0700 | [diff] [blame] | 323 | static int blkdev_write_begin(struct file *file, struct address_space *mapping, |
| 324 | loff_t pos, unsigned len, unsigned flags, |
| 325 | struct page **pagep, void **fsdata) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 326 | { |
Christoph Hellwig | 155130a | 2010-06-04 11:29:58 +0200 | [diff] [blame] | 327 | return block_write_begin(mapping, pos, len, flags, pagep, |
| 328 | blkdev_get_block); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 329 | } |
| 330 | |
Nick Piggin | 6272b5a | 2007-10-16 01:25:04 -0700 | [diff] [blame] | 331 | static int blkdev_write_end(struct file *file, struct address_space *mapping, |
| 332 | loff_t pos, unsigned len, unsigned copied, |
| 333 | struct page *page, void *fsdata) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 334 | { |
Nick Piggin | 6272b5a | 2007-10-16 01:25:04 -0700 | [diff] [blame] | 335 | int ret; |
| 336 | ret = block_write_end(file, mapping, pos, len, copied, page, fsdata); |
| 337 | |
| 338 | unlock_page(page); |
| 339 | page_cache_release(page); |
| 340 | |
| 341 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 342 | } |
| 343 | |
| 344 | /* |
| 345 | * private llseek: |
Josef "Jeff" Sipek | 0f7fc9e | 2006-12-08 02:36:35 -0800 | [diff] [blame] | 346 | * for a block special file file->f_path.dentry->d_inode->i_size is zero |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 347 | * so we compute the size by hand (just as in block_read/write above) |
| 348 | */ |
| 349 | static loff_t block_llseek(struct file *file, loff_t offset, int origin) |
| 350 | { |
| 351 | struct inode *bd_inode = file->f_mapping->host; |
| 352 | loff_t size; |
| 353 | loff_t retval; |
| 354 | |
Jes Sorensen | 1b1dcc1 | 2006-01-09 15:59:24 -0800 | [diff] [blame] | 355 | mutex_lock(&bd_inode->i_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 356 | size = i_size_read(bd_inode); |
| 357 | |
| 358 | switch (origin) { |
| 359 | case 2: |
| 360 | offset += size; |
| 361 | break; |
| 362 | case 1: |
| 363 | offset += file->f_pos; |
| 364 | } |
| 365 | retval = -EINVAL; |
| 366 | if (offset >= 0 && offset <= size) { |
| 367 | if (offset != file->f_pos) { |
| 368 | file->f_pos = offset; |
| 369 | } |
| 370 | retval = offset; |
| 371 | } |
Jes Sorensen | 1b1dcc1 | 2006-01-09 15:59:24 -0800 | [diff] [blame] | 372 | mutex_unlock(&bd_inode->i_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 373 | return retval; |
| 374 | } |
| 375 | |
Christoph Hellwig | 7ea8085 | 2010-05-26 17:53:25 +0200 | [diff] [blame] | 376 | int blkdev_fsync(struct file *filp, int datasync) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 377 | { |
Anton Blanchard | b8af67e | 2010-04-23 13:18:06 -0400 | [diff] [blame] | 378 | struct inode *bd_inode = filp->f_mapping->host; |
| 379 | struct block_device *bdev = I_BDEV(bd_inode); |
Christoph Hellwig | ab0a973 | 2009-10-29 14:14:04 +0100 | [diff] [blame] | 380 | int error; |
| 381 | |
Anton Blanchard | b8af67e | 2010-04-23 13:18:06 -0400 | [diff] [blame] | 382 | /* |
| 383 | * There is no need to serialise calls to blkdev_issue_flush with |
| 384 | * i_mutex and doing so causes performance issues with concurrent |
| 385 | * O_SYNC writers to a block device. |
| 386 | */ |
| 387 | mutex_unlock(&bd_inode->i_mutex); |
| 388 | |
Christoph Hellwig | dd3932e | 2010-09-16 20:51:46 +0200 | [diff] [blame] | 389 | error = blkdev_issue_flush(bdev, GFP_KERNEL, NULL); |
Christoph Hellwig | ab0a973 | 2009-10-29 14:14:04 +0100 | [diff] [blame] | 390 | if (error == -EOPNOTSUPP) |
| 391 | error = 0; |
Anton Blanchard | b8af67e | 2010-04-23 13:18:06 -0400 | [diff] [blame] | 392 | |
| 393 | mutex_lock(&bd_inode->i_mutex); |
| 394 | |
Christoph Hellwig | ab0a973 | 2009-10-29 14:14:04 +0100 | [diff] [blame] | 395 | return error; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 396 | } |
Andrew Morton | b1dd3b2 | 2010-04-06 14:35:00 -0700 | [diff] [blame] | 397 | EXPORT_SYMBOL(blkdev_fsync); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 398 | |
| 399 | /* |
| 400 | * pseudo-fs |
| 401 | */ |
| 402 | |
| 403 | static __cacheline_aligned_in_smp DEFINE_SPINLOCK(bdev_lock); |
Christoph Lameter | e18b890 | 2006-12-06 20:33:20 -0800 | [diff] [blame] | 404 | static struct kmem_cache * bdev_cachep __read_mostly; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 405 | |
| 406 | static struct inode *bdev_alloc_inode(struct super_block *sb) |
| 407 | { |
Christoph Lameter | e94b176 | 2006-12-06 20:33:17 -0800 | [diff] [blame] | 408 | struct bdev_inode *ei = kmem_cache_alloc(bdev_cachep, GFP_KERNEL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 409 | if (!ei) |
| 410 | return NULL; |
| 411 | return &ei->vfs_inode; |
| 412 | } |
| 413 | |
Nick Piggin | fa0d7e3 | 2011-01-07 17:49:49 +1100 | [diff] [blame] | 414 | static void bdev_i_callback(struct rcu_head *head) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 415 | { |
Nick Piggin | fa0d7e3 | 2011-01-07 17:49:49 +1100 | [diff] [blame] | 416 | struct inode *inode = container_of(head, struct inode, i_rcu); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 417 | struct bdev_inode *bdi = BDEV_I(inode); |
| 418 | |
Nick Piggin | fa0d7e3 | 2011-01-07 17:49:49 +1100 | [diff] [blame] | 419 | INIT_LIST_HEAD(&inode->i_dentry); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 420 | kmem_cache_free(bdev_cachep, bdi); |
| 421 | } |
| 422 | |
Nick Piggin | fa0d7e3 | 2011-01-07 17:49:49 +1100 | [diff] [blame] | 423 | static void bdev_destroy_inode(struct inode *inode) |
| 424 | { |
| 425 | call_rcu(&inode->i_rcu, bdev_i_callback); |
| 426 | } |
| 427 | |
Alexey Dobriyan | 51cc506 | 2008-07-25 19:45:34 -0700 | [diff] [blame] | 428 | static void init_once(void *foo) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 429 | { |
| 430 | struct bdev_inode *ei = (struct bdev_inode *) foo; |
| 431 | struct block_device *bdev = &ei->bdev; |
| 432 | |
Christoph Lameter | a35afb8 | 2007-05-16 22:10:57 -0700 | [diff] [blame] | 433 | memset(bdev, 0, sizeof(*bdev)); |
| 434 | mutex_init(&bdev->bd_mutex); |
Christoph Lameter | a35afb8 | 2007-05-16 22:10:57 -0700 | [diff] [blame] | 435 | INIT_LIST_HEAD(&bdev->bd_inodes); |
| 436 | INIT_LIST_HEAD(&bdev->bd_list); |
Tejun Heo | 49731ba | 2011-01-14 18:43:57 +0100 | [diff] [blame] | 437 | #ifdef CONFIG_SYSFS |
| 438 | INIT_LIST_HEAD(&bdev->bd_holder_disks); |
| 439 | #endif |
Christoph Lameter | a35afb8 | 2007-05-16 22:10:57 -0700 | [diff] [blame] | 440 | inode_init_once(&ei->vfs_inode); |
Takashi Sato | fcccf50 | 2009-01-09 16:40:59 -0800 | [diff] [blame] | 441 | /* Initialize mutex for freeze. */ |
| 442 | mutex_init(&bdev->bd_fsfreeze_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 443 | } |
| 444 | |
| 445 | static inline void __bd_forget(struct inode *inode) |
| 446 | { |
| 447 | list_del_init(&inode->i_devices); |
| 448 | inode->i_bdev = NULL; |
| 449 | inode->i_mapping = &inode->i_data; |
| 450 | } |
| 451 | |
Al Viro | b57922d | 2010-06-07 14:34:48 -0400 | [diff] [blame] | 452 | static void bdev_evict_inode(struct inode *inode) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 453 | { |
| 454 | struct block_device *bdev = &BDEV_I(inode)->bdev; |
| 455 | struct list_head *p; |
Al Viro | b57922d | 2010-06-07 14:34:48 -0400 | [diff] [blame] | 456 | truncate_inode_pages(&inode->i_data, 0); |
| 457 | invalidate_inode_buffers(inode); /* is it needed here? */ |
| 458 | end_writeback(inode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 459 | spin_lock(&bdev_lock); |
| 460 | while ( (p = bdev->bd_inodes.next) != &bdev->bd_inodes ) { |
| 461 | __bd_forget(list_entry(p, struct inode, i_devices)); |
| 462 | } |
| 463 | list_del_init(&bdev->bd_list); |
| 464 | spin_unlock(&bdev_lock); |
| 465 | } |
| 466 | |
Josef 'Jeff' Sipek | ee9b6d6 | 2007-02-12 00:55:41 -0800 | [diff] [blame] | 467 | static const struct super_operations bdev_sops = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 468 | .statfs = simple_statfs, |
| 469 | .alloc_inode = bdev_alloc_inode, |
| 470 | .destroy_inode = bdev_destroy_inode, |
| 471 | .drop_inode = generic_delete_inode, |
Al Viro | b57922d | 2010-06-07 14:34:48 -0400 | [diff] [blame] | 472 | .evict_inode = bdev_evict_inode, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 473 | }; |
| 474 | |
Al Viro | 51139ad | 2010-07-25 23:47:46 +0400 | [diff] [blame] | 475 | static struct dentry *bd_mount(struct file_system_type *fs_type, |
| 476 | int flags, const char *dev_name, void *data) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 477 | { |
Al Viro | c74a1cb | 2011-01-12 16:59:34 -0500 | [diff] [blame] | 478 | return mount_pseudo(fs_type, "bdev:", &bdev_sops, NULL, 0x62646576); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 479 | } |
| 480 | |
| 481 | static struct file_system_type bd_type = { |
| 482 | .name = "bdev", |
Al Viro | 51139ad | 2010-07-25 23:47:46 +0400 | [diff] [blame] | 483 | .mount = bd_mount, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 484 | .kill_sb = kill_anon_super, |
| 485 | }; |
| 486 | |
Denis ChengRq | c2acf7b | 2008-12-01 14:34:56 -0800 | [diff] [blame] | 487 | struct super_block *blockdev_superblock __read_mostly; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 488 | |
| 489 | void __init bdev_cache_init(void) |
| 490 | { |
| 491 | int err; |
Denis ChengRq | c2acf7b | 2008-12-01 14:34:56 -0800 | [diff] [blame] | 492 | struct vfsmount *bd_mnt; |
| 493 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 494 | bdev_cachep = kmem_cache_create("bdev_cache", sizeof(struct bdev_inode), |
Paul Jackson | fffb60f | 2006-03-24 03:16:06 -0800 | [diff] [blame] | 495 | 0, (SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT| |
| 496 | SLAB_MEM_SPREAD|SLAB_PANIC), |
Paul Mundt | 20c2df8 | 2007-07-20 10:11:58 +0900 | [diff] [blame] | 497 | init_once); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 498 | err = register_filesystem(&bd_type); |
| 499 | if (err) |
| 500 | panic("Cannot register bdev pseudo-fs"); |
| 501 | bd_mnt = kern_mount(&bd_type); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 502 | if (IS_ERR(bd_mnt)) |
| 503 | panic("Cannot create bdev pseudo-fs"); |
Catalin Marinas | 2e1483c | 2009-06-11 13:24:13 +0100 | [diff] [blame] | 504 | /* |
| 505 | * This vfsmount structure is only used to obtain the |
| 506 | * blockdev_superblock, so tell kmemleak not to report it. |
| 507 | */ |
| 508 | kmemleak_not_leak(bd_mnt); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 509 | blockdev_superblock = bd_mnt->mnt_sb; /* For writeback */ |
| 510 | } |
| 511 | |
| 512 | /* |
| 513 | * Most likely _very_ bad one - but then it's hardly critical for small |
| 514 | * /dev and can be fixed when somebody will need really large one. |
| 515 | * Keep in mind that it will be fed through icache hash function too. |
| 516 | */ |
| 517 | static inline unsigned long hash(dev_t dev) |
| 518 | { |
| 519 | return MAJOR(dev)+MINOR(dev); |
| 520 | } |
| 521 | |
| 522 | static int bdev_test(struct inode *inode, void *data) |
| 523 | { |
| 524 | return BDEV_I(inode)->bdev.bd_dev == *(dev_t *)data; |
| 525 | } |
| 526 | |
| 527 | static int bdev_set(struct inode *inode, void *data) |
| 528 | { |
| 529 | BDEV_I(inode)->bdev.bd_dev = *(dev_t *)data; |
| 530 | return 0; |
| 531 | } |
| 532 | |
| 533 | static LIST_HEAD(all_bdevs); |
| 534 | |
| 535 | struct block_device *bdget(dev_t dev) |
| 536 | { |
| 537 | struct block_device *bdev; |
| 538 | struct inode *inode; |
| 539 | |
Denis ChengRq | c2acf7b | 2008-12-01 14:34:56 -0800 | [diff] [blame] | 540 | inode = iget5_locked(blockdev_superblock, hash(dev), |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 541 | bdev_test, bdev_set, &dev); |
| 542 | |
| 543 | if (!inode) |
| 544 | return NULL; |
| 545 | |
| 546 | bdev = &BDEV_I(inode)->bdev; |
| 547 | |
| 548 | if (inode->i_state & I_NEW) { |
| 549 | bdev->bd_contains = NULL; |
| 550 | bdev->bd_inode = inode; |
| 551 | bdev->bd_block_size = (1 << inode->i_blkbits); |
| 552 | bdev->bd_part_count = 0; |
| 553 | bdev->bd_invalidated = 0; |
| 554 | inode->i_mode = S_IFBLK; |
| 555 | inode->i_rdev = dev; |
| 556 | inode->i_bdev = bdev; |
| 557 | inode->i_data.a_ops = &def_blk_aops; |
| 558 | mapping_set_gfp_mask(&inode->i_data, GFP_USER); |
| 559 | inode->i_data.backing_dev_info = &default_backing_dev_info; |
| 560 | spin_lock(&bdev_lock); |
| 561 | list_add(&bdev->bd_list, &all_bdevs); |
| 562 | spin_unlock(&bdev_lock); |
| 563 | unlock_new_inode(inode); |
| 564 | } |
| 565 | return bdev; |
| 566 | } |
| 567 | |
| 568 | EXPORT_SYMBOL(bdget); |
| 569 | |
Alan Jenkins | dddac6a | 2009-07-29 21:07:55 +0200 | [diff] [blame] | 570 | /** |
| 571 | * bdgrab -- Grab a reference to an already referenced block device |
| 572 | * @bdev: Block device to grab a reference to. |
| 573 | */ |
| 574 | struct block_device *bdgrab(struct block_device *bdev) |
| 575 | { |
Al Viro | 7de9c6e | 2010-10-23 11:11:40 -0400 | [diff] [blame] | 576 | ihold(bdev->bd_inode); |
Alan Jenkins | dddac6a | 2009-07-29 21:07:55 +0200 | [diff] [blame] | 577 | return bdev; |
| 578 | } |
| 579 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 580 | long nr_blockdev_pages(void) |
| 581 | { |
Matthias Kaehlcke | 203a293 | 2007-07-15 23:40:23 -0700 | [diff] [blame] | 582 | struct block_device *bdev; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 583 | long ret = 0; |
| 584 | spin_lock(&bdev_lock); |
Matthias Kaehlcke | 203a293 | 2007-07-15 23:40:23 -0700 | [diff] [blame] | 585 | list_for_each_entry(bdev, &all_bdevs, bd_list) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 586 | ret += bdev->bd_inode->i_mapping->nrpages; |
| 587 | } |
| 588 | spin_unlock(&bdev_lock); |
| 589 | return ret; |
| 590 | } |
| 591 | |
| 592 | void bdput(struct block_device *bdev) |
| 593 | { |
| 594 | iput(bdev->bd_inode); |
| 595 | } |
| 596 | |
| 597 | EXPORT_SYMBOL(bdput); |
| 598 | |
| 599 | static struct block_device *bd_acquire(struct inode *inode) |
| 600 | { |
| 601 | struct block_device *bdev; |
OGAWA Hirofumi | 09d967c | 2006-06-22 14:47:21 -0700 | [diff] [blame] | 602 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 603 | spin_lock(&bdev_lock); |
| 604 | bdev = inode->i_bdev; |
OGAWA Hirofumi | 09d967c | 2006-06-22 14:47:21 -0700 | [diff] [blame] | 605 | if (bdev) { |
Al Viro | 7de9c6e | 2010-10-23 11:11:40 -0400 | [diff] [blame] | 606 | ihold(bdev->bd_inode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 607 | spin_unlock(&bdev_lock); |
| 608 | return bdev; |
| 609 | } |
| 610 | spin_unlock(&bdev_lock); |
OGAWA Hirofumi | 09d967c | 2006-06-22 14:47:21 -0700 | [diff] [blame] | 611 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 612 | bdev = bdget(inode->i_rdev); |
| 613 | if (bdev) { |
| 614 | spin_lock(&bdev_lock); |
OGAWA Hirofumi | 09d967c | 2006-06-22 14:47:21 -0700 | [diff] [blame] | 615 | if (!inode->i_bdev) { |
| 616 | /* |
Al Viro | 7de9c6e | 2010-10-23 11:11:40 -0400 | [diff] [blame] | 617 | * We take an additional reference to bd_inode, |
OGAWA Hirofumi | 09d967c | 2006-06-22 14:47:21 -0700 | [diff] [blame] | 618 | * and it's released in clear_inode() of inode. |
| 619 | * So, we can access it via ->i_mapping always |
| 620 | * without igrab(). |
| 621 | */ |
Al Viro | 7de9c6e | 2010-10-23 11:11:40 -0400 | [diff] [blame] | 622 | ihold(bdev->bd_inode); |
OGAWA Hirofumi | 09d967c | 2006-06-22 14:47:21 -0700 | [diff] [blame] | 623 | inode->i_bdev = bdev; |
| 624 | inode->i_mapping = bdev->bd_inode->i_mapping; |
| 625 | list_add(&inode->i_devices, &bdev->bd_inodes); |
| 626 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 627 | spin_unlock(&bdev_lock); |
| 628 | } |
| 629 | return bdev; |
| 630 | } |
| 631 | |
| 632 | /* Call when you free inode */ |
| 633 | |
| 634 | void bd_forget(struct inode *inode) |
| 635 | { |
OGAWA Hirofumi | 09d967c | 2006-06-22 14:47:21 -0700 | [diff] [blame] | 636 | struct block_device *bdev = NULL; |
| 637 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 638 | spin_lock(&bdev_lock); |
OGAWA Hirofumi | 09d967c | 2006-06-22 14:47:21 -0700 | [diff] [blame] | 639 | if (inode->i_bdev) { |
Denis ChengRq | c2acf7b | 2008-12-01 14:34:56 -0800 | [diff] [blame] | 640 | if (!sb_is_blkdev_sb(inode->i_sb)) |
OGAWA Hirofumi | 09d967c | 2006-06-22 14:47:21 -0700 | [diff] [blame] | 641 | bdev = inode->i_bdev; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 642 | __bd_forget(inode); |
OGAWA Hirofumi | 09d967c | 2006-06-22 14:47:21 -0700 | [diff] [blame] | 643 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 644 | spin_unlock(&bdev_lock); |
OGAWA Hirofumi | 09d967c | 2006-06-22 14:47:21 -0700 | [diff] [blame] | 645 | |
| 646 | if (bdev) |
| 647 | iput(bdev->bd_inode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 648 | } |
| 649 | |
Tejun Heo | 1a3cbbc | 2010-04-07 18:52:29 +0900 | [diff] [blame] | 650 | /** |
| 651 | * bd_may_claim - test whether a block device can be claimed |
| 652 | * @bdev: block device of interest |
| 653 | * @whole: whole block device containing @bdev, may equal @bdev |
| 654 | * @holder: holder trying to claim @bdev |
| 655 | * |
Lucas De Marchi | 25985ed | 2011-03-30 22:57:33 -0300 | [diff] [blame] | 656 | * Test whether @bdev can be claimed by @holder. |
Tejun Heo | 1a3cbbc | 2010-04-07 18:52:29 +0900 | [diff] [blame] | 657 | * |
| 658 | * CONTEXT: |
| 659 | * spin_lock(&bdev_lock). |
| 660 | * |
| 661 | * RETURNS: |
| 662 | * %true if @bdev can be claimed, %false otherwise. |
| 663 | */ |
| 664 | static bool bd_may_claim(struct block_device *bdev, struct block_device *whole, |
| 665 | void *holder) |
| 666 | { |
| 667 | if (bdev->bd_holder == holder) |
| 668 | return true; /* already a holder */ |
| 669 | else if (bdev->bd_holder != NULL) |
| 670 | return false; /* held by someone else */ |
| 671 | else if (bdev->bd_contains == bdev) |
| 672 | return true; /* is a whole device which isn't held */ |
| 673 | |
Tejun Heo | e525fd8 | 2010-11-13 11:55:17 +0100 | [diff] [blame] | 674 | else if (whole->bd_holder == bd_may_claim) |
Tejun Heo | 1a3cbbc | 2010-04-07 18:52:29 +0900 | [diff] [blame] | 675 | return true; /* is a partition of a device that is being partitioned */ |
| 676 | else if (whole->bd_holder != NULL) |
| 677 | return false; /* is a partition of a held device */ |
| 678 | else |
| 679 | return true; /* is a partition of an un-held device */ |
| 680 | } |
| 681 | |
| 682 | /** |
Tejun Heo | 6b4517a | 2010-04-07 18:53:59 +0900 | [diff] [blame] | 683 | * bd_prepare_to_claim - prepare to claim a block device |
| 684 | * @bdev: block device of interest |
| 685 | * @whole: the whole device containing @bdev, may equal @bdev |
| 686 | * @holder: holder trying to claim @bdev |
| 687 | * |
| 688 | * Prepare to claim @bdev. This function fails if @bdev is already |
| 689 | * claimed by another holder and waits if another claiming is in |
| 690 | * progress. This function doesn't actually claim. On successful |
| 691 | * return, the caller has ownership of bd_claiming and bd_holder[s]. |
| 692 | * |
| 693 | * CONTEXT: |
| 694 | * spin_lock(&bdev_lock). Might release bdev_lock, sleep and regrab |
| 695 | * it multiple times. |
| 696 | * |
| 697 | * RETURNS: |
| 698 | * 0 if @bdev can be claimed, -EBUSY otherwise. |
| 699 | */ |
| 700 | static int bd_prepare_to_claim(struct block_device *bdev, |
| 701 | struct block_device *whole, void *holder) |
| 702 | { |
| 703 | retry: |
| 704 | /* if someone else claimed, fail */ |
| 705 | if (!bd_may_claim(bdev, whole, holder)) |
| 706 | return -EBUSY; |
| 707 | |
Tejun Heo | e75aa85 | 2010-08-04 17:59:39 +0200 | [diff] [blame] | 708 | /* if claiming is already in progress, wait for it to finish */ |
| 709 | if (whole->bd_claiming) { |
Tejun Heo | 6b4517a | 2010-04-07 18:53:59 +0900 | [diff] [blame] | 710 | wait_queue_head_t *wq = bit_waitqueue(&whole->bd_claiming, 0); |
| 711 | DEFINE_WAIT(wait); |
| 712 | |
| 713 | prepare_to_wait(wq, &wait, TASK_UNINTERRUPTIBLE); |
| 714 | spin_unlock(&bdev_lock); |
| 715 | schedule(); |
| 716 | finish_wait(wq, &wait); |
| 717 | spin_lock(&bdev_lock); |
| 718 | goto retry; |
| 719 | } |
| 720 | |
| 721 | /* yay, all mine */ |
| 722 | return 0; |
| 723 | } |
| 724 | |
| 725 | /** |
| 726 | * bd_start_claiming - start claiming a block device |
| 727 | * @bdev: block device of interest |
| 728 | * @holder: holder trying to claim @bdev |
| 729 | * |
| 730 | * @bdev is about to be opened exclusively. Check @bdev can be opened |
| 731 | * exclusively and mark that an exclusive open is in progress. Each |
| 732 | * successful call to this function must be matched with a call to |
Nick Piggin | b001836 | 2010-05-26 01:51:19 +1000 | [diff] [blame] | 733 | * either bd_finish_claiming() or bd_abort_claiming() (which do not |
| 734 | * fail). |
| 735 | * |
| 736 | * This function is used to gain exclusive access to the block device |
| 737 | * without actually causing other exclusive open attempts to fail. It |
| 738 | * should be used when the open sequence itself requires exclusive |
| 739 | * access but may subsequently fail. |
Tejun Heo | 6b4517a | 2010-04-07 18:53:59 +0900 | [diff] [blame] | 740 | * |
| 741 | * CONTEXT: |
| 742 | * Might sleep. |
| 743 | * |
| 744 | * RETURNS: |
| 745 | * Pointer to the block device containing @bdev on success, ERR_PTR() |
| 746 | * value on failure. |
| 747 | */ |
| 748 | static struct block_device *bd_start_claiming(struct block_device *bdev, |
| 749 | void *holder) |
| 750 | { |
| 751 | struct gendisk *disk; |
| 752 | struct block_device *whole; |
| 753 | int partno, err; |
| 754 | |
| 755 | might_sleep(); |
| 756 | |
| 757 | /* |
| 758 | * @bdev might not have been initialized properly yet, look up |
| 759 | * and grab the outer block device the hard way. |
| 760 | */ |
| 761 | disk = get_gendisk(bdev->bd_dev, &partno); |
| 762 | if (!disk) |
| 763 | return ERR_PTR(-ENXIO); |
| 764 | |
| 765 | whole = bdget_disk(disk, 0); |
Nick Piggin | cf34257 | 2010-05-26 01:50:21 +1000 | [diff] [blame] | 766 | module_put(disk->fops->owner); |
Tejun Heo | 6b4517a | 2010-04-07 18:53:59 +0900 | [diff] [blame] | 767 | put_disk(disk); |
| 768 | if (!whole) |
| 769 | return ERR_PTR(-ENOMEM); |
| 770 | |
| 771 | /* prepare to claim, if successful, mark claiming in progress */ |
| 772 | spin_lock(&bdev_lock); |
| 773 | |
| 774 | err = bd_prepare_to_claim(bdev, whole, holder); |
| 775 | if (err == 0) { |
| 776 | whole->bd_claiming = holder; |
| 777 | spin_unlock(&bdev_lock); |
| 778 | return whole; |
| 779 | } else { |
| 780 | spin_unlock(&bdev_lock); |
| 781 | bdput(whole); |
| 782 | return ERR_PTR(err); |
| 783 | } |
| 784 | } |
| 785 | |
Jun'ichi Nomura | 641dc63 | 2006-03-27 01:17:57 -0800 | [diff] [blame] | 786 | #ifdef CONFIG_SYSFS |
Tejun Heo | 49731ba | 2011-01-14 18:43:57 +0100 | [diff] [blame] | 787 | struct bd_holder_disk { |
| 788 | struct list_head list; |
| 789 | struct gendisk *disk; |
| 790 | int refcnt; |
| 791 | }; |
| 792 | |
| 793 | static struct bd_holder_disk *bd_find_holder_disk(struct block_device *bdev, |
| 794 | struct gendisk *disk) |
| 795 | { |
| 796 | struct bd_holder_disk *holder; |
| 797 | |
| 798 | list_for_each_entry(holder, &bdev->bd_holder_disks, list) |
| 799 | if (holder->disk == disk) |
| 800 | return holder; |
| 801 | return NULL; |
| 802 | } |
| 803 | |
Andrew Morton | 4d7dd8f | 2006-09-29 01:58:56 -0700 | [diff] [blame] | 804 | static int add_symlink(struct kobject *from, struct kobject *to) |
Jun'ichi Nomura | 641dc63 | 2006-03-27 01:17:57 -0800 | [diff] [blame] | 805 | { |
Andrew Morton | 4d7dd8f | 2006-09-29 01:58:56 -0700 | [diff] [blame] | 806 | return sysfs_create_link(from, to, kobject_name(to)); |
Jun'ichi Nomura | 641dc63 | 2006-03-27 01:17:57 -0800 | [diff] [blame] | 807 | } |
| 808 | |
| 809 | static void del_symlink(struct kobject *from, struct kobject *to) |
| 810 | { |
Jun'ichi Nomura | 641dc63 | 2006-03-27 01:17:57 -0800 | [diff] [blame] | 811 | sysfs_remove_link(from, kobject_name(to)); |
| 812 | } |
| 813 | |
Jun'ichi Nomura | 641dc63 | 2006-03-27 01:17:57 -0800 | [diff] [blame] | 814 | /** |
Tejun Heo | e09b457 | 2010-11-13 11:55:17 +0100 | [diff] [blame] | 815 | * bd_link_disk_holder - create symlinks between holding disk and slave bdev |
| 816 | * @bdev: the claimed slave bdev |
| 817 | * @disk: the holding disk |
Jun'ichi Nomura | df6c0cd | 2006-10-30 16:23:56 -0500 | [diff] [blame] | 818 | * |
Tejun Heo | 49731ba | 2011-01-14 18:43:57 +0100 | [diff] [blame] | 819 | * DON'T USE THIS UNLESS YOU'RE ALREADY USING IT. |
| 820 | * |
Tejun Heo | e09b457 | 2010-11-13 11:55:17 +0100 | [diff] [blame] | 821 | * This functions creates the following sysfs symlinks. |
Jun'ichi Nomura | df6c0cd | 2006-10-30 16:23:56 -0500 | [diff] [blame] | 822 | * |
Tejun Heo | e09b457 | 2010-11-13 11:55:17 +0100 | [diff] [blame] | 823 | * - from "slaves" directory of the holder @disk to the claimed @bdev |
| 824 | * - from "holders" directory of the @bdev to the holder @disk |
| 825 | * |
| 826 | * For example, if /dev/dm-0 maps to /dev/sda and disk for dm-0 is |
| 827 | * passed to bd_link_disk_holder(), then: |
| 828 | * |
| 829 | * /sys/block/dm-0/slaves/sda --> /sys/block/sda |
| 830 | * /sys/block/sda/holders/dm-0 --> /sys/block/dm-0 |
| 831 | * |
| 832 | * The caller must have claimed @bdev before calling this function and |
| 833 | * ensure that both @bdev and @disk are valid during the creation and |
| 834 | * lifetime of these symlinks. |
| 835 | * |
| 836 | * CONTEXT: |
| 837 | * Might sleep. |
| 838 | * |
| 839 | * RETURNS: |
| 840 | * 0 on success, -errno on failure. |
Jun'ichi Nomura | df6c0cd | 2006-10-30 16:23:56 -0500 | [diff] [blame] | 841 | */ |
Tejun Heo | e09b457 | 2010-11-13 11:55:17 +0100 | [diff] [blame] | 842 | int bd_link_disk_holder(struct block_device *bdev, struct gendisk *disk) |
Jun'ichi Nomura | df6c0cd | 2006-10-30 16:23:56 -0500 | [diff] [blame] | 843 | { |
Tejun Heo | 49731ba | 2011-01-14 18:43:57 +0100 | [diff] [blame] | 844 | struct bd_holder_disk *holder; |
Tejun Heo | e09b457 | 2010-11-13 11:55:17 +0100 | [diff] [blame] | 845 | int ret = 0; |
Jun'ichi Nomura | 641dc63 | 2006-03-27 01:17:57 -0800 | [diff] [blame] | 846 | |
Peter Zijlstra | 2e7b651 | 2006-12-08 02:36:13 -0800 | [diff] [blame] | 847 | mutex_lock(&bdev->bd_mutex); |
Jun'ichi Nomura | df6c0cd | 2006-10-30 16:23:56 -0500 | [diff] [blame] | 848 | |
Tejun Heo | 49731ba | 2011-01-14 18:43:57 +0100 | [diff] [blame] | 849 | WARN_ON_ONCE(!bdev->bd_holder); |
Johannes Weiner | 4e91672 | 2007-07-15 23:41:25 -0700 | [diff] [blame] | 850 | |
Tejun Heo | e09b457 | 2010-11-13 11:55:17 +0100 | [diff] [blame] | 851 | /* FIXME: remove the following once add_disk() handles errors */ |
| 852 | if (WARN_ON(!disk->slave_dir || !bdev->bd_part->holder_dir)) |
| 853 | goto out_unlock; |
Johannes Weiner | 4e91672 | 2007-07-15 23:41:25 -0700 | [diff] [blame] | 854 | |
Tejun Heo | 49731ba | 2011-01-14 18:43:57 +0100 | [diff] [blame] | 855 | holder = bd_find_holder_disk(bdev, disk); |
| 856 | if (holder) { |
| 857 | holder->refcnt++; |
Tejun Heo | e09b457 | 2010-11-13 11:55:17 +0100 | [diff] [blame] | 858 | goto out_unlock; |
| 859 | } |
| 860 | |
Tejun Heo | 49731ba | 2011-01-14 18:43:57 +0100 | [diff] [blame] | 861 | holder = kzalloc(sizeof(*holder), GFP_KERNEL); |
| 862 | if (!holder) { |
| 863 | ret = -ENOMEM; |
| 864 | goto out_unlock; |
| 865 | } |
| 866 | |
| 867 | INIT_LIST_HEAD(&holder->list); |
| 868 | holder->disk = disk; |
| 869 | holder->refcnt = 1; |
| 870 | |
| 871 | ret = add_symlink(disk->slave_dir, &part_to_dev(bdev->bd_part)->kobj); |
| 872 | if (ret) |
| 873 | goto out_free; |
| 874 | |
| 875 | ret = add_symlink(bdev->bd_part->holder_dir, &disk_to_dev(disk)->kobj); |
| 876 | if (ret) |
| 877 | goto out_del; |
Tejun Heo | e7407d1 | 2011-02-24 09:56:32 +0100 | [diff] [blame] | 878 | /* |
| 879 | * bdev could be deleted beneath us which would implicitly destroy |
| 880 | * the holder directory. Hold on to it. |
| 881 | */ |
| 882 | kobject_get(bdev->bd_part->holder_dir); |
Tejun Heo | 49731ba | 2011-01-14 18:43:57 +0100 | [diff] [blame] | 883 | |
| 884 | list_add(&holder->list, &bdev->bd_holder_disks); |
| 885 | goto out_unlock; |
| 886 | |
| 887 | out_del: |
| 888 | del_symlink(disk->slave_dir, &part_to_dev(bdev->bd_part)->kobj); |
| 889 | out_free: |
| 890 | kfree(holder); |
Tejun Heo | e09b457 | 2010-11-13 11:55:17 +0100 | [diff] [blame] | 891 | out_unlock: |
Jun'ichi Nomura | b4cf1b7 | 2006-03-27 01:18:00 -0800 | [diff] [blame] | 892 | mutex_unlock(&bdev->bd_mutex); |
Tejun Heo | e09b457 | 2010-11-13 11:55:17 +0100 | [diff] [blame] | 893 | return ret; |
Jun'ichi Nomura | 641dc63 | 2006-03-27 01:17:57 -0800 | [diff] [blame] | 894 | } |
Tejun Heo | e09b457 | 2010-11-13 11:55:17 +0100 | [diff] [blame] | 895 | EXPORT_SYMBOL_GPL(bd_link_disk_holder); |
Jun'ichi Nomura | 641dc63 | 2006-03-27 01:17:57 -0800 | [diff] [blame] | 896 | |
Tejun Heo | 49731ba | 2011-01-14 18:43:57 +0100 | [diff] [blame] | 897 | /** |
| 898 | * bd_unlink_disk_holder - destroy symlinks created by bd_link_disk_holder() |
| 899 | * @bdev: the calimed slave bdev |
| 900 | * @disk: the holding disk |
| 901 | * |
| 902 | * DON'T USE THIS UNLESS YOU'RE ALREADY USING IT. |
| 903 | * |
| 904 | * CONTEXT: |
| 905 | * Might sleep. |
| 906 | */ |
| 907 | void bd_unlink_disk_holder(struct block_device *bdev, struct gendisk *disk) |
Jun'ichi Nomura | 641dc63 | 2006-03-27 01:17:57 -0800 | [diff] [blame] | 908 | { |
Tejun Heo | 49731ba | 2011-01-14 18:43:57 +0100 | [diff] [blame] | 909 | struct bd_holder_disk *holder; |
Tejun Heo | e09b457 | 2010-11-13 11:55:17 +0100 | [diff] [blame] | 910 | |
Tejun Heo | 49731ba | 2011-01-14 18:43:57 +0100 | [diff] [blame] | 911 | mutex_lock(&bdev->bd_mutex); |
Jun'ichi Nomura | 641dc63 | 2006-03-27 01:17:57 -0800 | [diff] [blame] | 912 | |
Tejun Heo | 49731ba | 2011-01-14 18:43:57 +0100 | [diff] [blame] | 913 | holder = bd_find_holder_disk(bdev, disk); |
| 914 | |
| 915 | if (!WARN_ON_ONCE(holder == NULL) && !--holder->refcnt) { |
| 916 | del_symlink(disk->slave_dir, &part_to_dev(bdev->bd_part)->kobj); |
| 917 | del_symlink(bdev->bd_part->holder_dir, |
| 918 | &disk_to_dev(disk)->kobj); |
Tejun Heo | e7407d1 | 2011-02-24 09:56:32 +0100 | [diff] [blame] | 919 | kobject_put(bdev->bd_part->holder_dir); |
Tejun Heo | 49731ba | 2011-01-14 18:43:57 +0100 | [diff] [blame] | 920 | list_del_init(&holder->list); |
| 921 | kfree(holder); |
| 922 | } |
| 923 | |
| 924 | mutex_unlock(&bdev->bd_mutex); |
Jun'ichi Nomura | 641dc63 | 2006-03-27 01:17:57 -0800 | [diff] [blame] | 925 | } |
Tejun Heo | 49731ba | 2011-01-14 18:43:57 +0100 | [diff] [blame] | 926 | EXPORT_SYMBOL_GPL(bd_unlink_disk_holder); |
Jun'ichi Nomura | 641dc63 | 2006-03-27 01:17:57 -0800 | [diff] [blame] | 927 | #endif |
| 928 | |
Andrew Patterson | 0c002c2 | 2008-09-04 14:27:20 -0600 | [diff] [blame] | 929 | /** |
Andrew Patterson | 56ade44 | 2008-09-04 14:27:40 -0600 | [diff] [blame] | 930 | * flush_disk - invalidates all buffer-cache entries on a disk |
| 931 | * |
| 932 | * @bdev: struct block device to be flushed |
Randy Dunlap | e6eb5ce | 2011-02-26 10:54:00 -0800 | [diff] [blame] | 933 | * @kill_dirty: flag to guide handling of dirty inodes |
Andrew Patterson | 56ade44 | 2008-09-04 14:27:40 -0600 | [diff] [blame] | 934 | * |
| 935 | * Invalidates all buffer-cache entries on a disk. It should be called |
| 936 | * when a disk has been changed -- either by a media change or online |
| 937 | * resize. |
| 938 | */ |
NeilBrown | 93b270f | 2011-02-24 17:25:47 +1100 | [diff] [blame] | 939 | static void flush_disk(struct block_device *bdev, bool kill_dirty) |
Andrew Patterson | 56ade44 | 2008-09-04 14:27:40 -0600 | [diff] [blame] | 940 | { |
NeilBrown | 93b270f | 2011-02-24 17:25:47 +1100 | [diff] [blame] | 941 | if (__invalidate_device(bdev, kill_dirty)) { |
Andrew Patterson | 56ade44 | 2008-09-04 14:27:40 -0600 | [diff] [blame] | 942 | char name[BDEVNAME_SIZE] = ""; |
| 943 | |
| 944 | if (bdev->bd_disk) |
| 945 | disk_name(bdev->bd_disk, 0, name); |
| 946 | printk(KERN_WARNING "VFS: busy inodes on changed media or " |
| 947 | "resized disk %s\n", name); |
| 948 | } |
| 949 | |
| 950 | if (!bdev->bd_disk) |
| 951 | return; |
| 952 | if (disk_partitionable(bdev->bd_disk)) |
| 953 | bdev->bd_invalidated = 1; |
| 954 | } |
| 955 | |
| 956 | /** |
Randy Dunlap | 57d1b53 | 2008-10-09 10:42:38 +0200 | [diff] [blame] | 957 | * check_disk_size_change - checks for disk size change and adjusts bdev size. |
Andrew Patterson | c3279d1 | 2008-09-04 14:27:25 -0600 | [diff] [blame] | 958 | * @disk: struct gendisk to check |
| 959 | * @bdev: struct bdev to adjust. |
| 960 | * |
| 961 | * This routine checks to see if the bdev size does not match the disk size |
| 962 | * and adjusts it if it differs. |
| 963 | */ |
| 964 | void check_disk_size_change(struct gendisk *disk, struct block_device *bdev) |
| 965 | { |
| 966 | loff_t disk_size, bdev_size; |
| 967 | |
| 968 | disk_size = (loff_t)get_capacity(disk) << 9; |
| 969 | bdev_size = i_size_read(bdev->bd_inode); |
| 970 | if (disk_size != bdev_size) { |
| 971 | char name[BDEVNAME_SIZE]; |
| 972 | |
| 973 | disk_name(disk, 0, name); |
| 974 | printk(KERN_INFO |
| 975 | "%s: detected capacity change from %lld to %lld\n", |
| 976 | name, bdev_size, disk_size); |
| 977 | i_size_write(bdev->bd_inode, disk_size); |
NeilBrown | 93b270f | 2011-02-24 17:25:47 +1100 | [diff] [blame] | 978 | flush_disk(bdev, false); |
Andrew Patterson | c3279d1 | 2008-09-04 14:27:25 -0600 | [diff] [blame] | 979 | } |
| 980 | } |
| 981 | EXPORT_SYMBOL(check_disk_size_change); |
| 982 | |
| 983 | /** |
Randy Dunlap | 57d1b53 | 2008-10-09 10:42:38 +0200 | [diff] [blame] | 984 | * revalidate_disk - wrapper for lower-level driver's revalidate_disk call-back |
Andrew Patterson | 0c002c2 | 2008-09-04 14:27:20 -0600 | [diff] [blame] | 985 | * @disk: struct gendisk to be revalidated |
| 986 | * |
| 987 | * This routine is a wrapper for lower-level driver's revalidate_disk |
| 988 | * call-backs. It is used to do common pre and post operations needed |
| 989 | * for all revalidate_disk operations. |
| 990 | */ |
| 991 | int revalidate_disk(struct gendisk *disk) |
| 992 | { |
Andrew Patterson | c3279d1 | 2008-09-04 14:27:25 -0600 | [diff] [blame] | 993 | struct block_device *bdev; |
Andrew Patterson | 0c002c2 | 2008-09-04 14:27:20 -0600 | [diff] [blame] | 994 | int ret = 0; |
| 995 | |
| 996 | if (disk->fops->revalidate_disk) |
| 997 | ret = disk->fops->revalidate_disk(disk); |
| 998 | |
Andrew Patterson | c3279d1 | 2008-09-04 14:27:25 -0600 | [diff] [blame] | 999 | bdev = bdget_disk(disk, 0); |
| 1000 | if (!bdev) |
| 1001 | return ret; |
| 1002 | |
| 1003 | mutex_lock(&bdev->bd_mutex); |
| 1004 | check_disk_size_change(disk, bdev); |
| 1005 | mutex_unlock(&bdev->bd_mutex); |
| 1006 | bdput(bdev); |
Andrew Patterson | 0c002c2 | 2008-09-04 14:27:20 -0600 | [diff] [blame] | 1007 | return ret; |
| 1008 | } |
| 1009 | EXPORT_SYMBOL(revalidate_disk); |
| 1010 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1011 | /* |
| 1012 | * This routine checks whether a removable media has been changed, |
| 1013 | * and invalidates all buffer-cache-entries in that case. This |
| 1014 | * is a relatively slow routine, so we have to try to minimize using |
| 1015 | * it. Thus it is called only upon a 'mount' or 'open'. This |
| 1016 | * is the best way of combining speed and utility, I think. |
| 1017 | * People changing diskettes in the middle of an operation deserve |
| 1018 | * to lose :-) |
| 1019 | */ |
| 1020 | int check_disk_change(struct block_device *bdev) |
| 1021 | { |
| 1022 | struct gendisk *disk = bdev->bd_disk; |
Alexey Dobriyan | 83d5cde | 2009-09-21 17:01:13 -0700 | [diff] [blame] | 1023 | const struct block_device_operations *bdops = disk->fops; |
Tejun Heo | 77ea887 | 2010-12-08 20:57:37 +0100 | [diff] [blame] | 1024 | unsigned int events; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1025 | |
Tejun Heo | 77ea887 | 2010-12-08 20:57:37 +0100 | [diff] [blame] | 1026 | events = disk_clear_events(disk, DISK_EVENT_MEDIA_CHANGE | |
| 1027 | DISK_EVENT_EJECT_REQUEST); |
| 1028 | if (!(events & DISK_EVENT_MEDIA_CHANGE)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1029 | return 0; |
| 1030 | |
NeilBrown | 93b270f | 2011-02-24 17:25:47 +1100 | [diff] [blame] | 1031 | flush_disk(bdev, true); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1032 | if (bdops->revalidate_disk) |
| 1033 | bdops->revalidate_disk(bdev->bd_disk); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1034 | return 1; |
| 1035 | } |
| 1036 | |
| 1037 | EXPORT_SYMBOL(check_disk_change); |
| 1038 | |
| 1039 | void bd_set_size(struct block_device *bdev, loff_t size) |
| 1040 | { |
Martin K. Petersen | e1defc4 | 2009-05-22 17:17:49 -0400 | [diff] [blame] | 1041 | unsigned bsize = bdev_logical_block_size(bdev); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1042 | |
| 1043 | bdev->bd_inode->i_size = size; |
| 1044 | while (bsize < PAGE_CACHE_SIZE) { |
| 1045 | if (size & bsize) |
| 1046 | break; |
| 1047 | bsize <<= 1; |
| 1048 | } |
| 1049 | bdev->bd_block_size = bsize; |
| 1050 | bdev->bd_inode->i_blkbits = blksize_bits(bsize); |
| 1051 | } |
| 1052 | EXPORT_SYMBOL(bd_set_size); |
| 1053 | |
Al Viro | 9a1c354 | 2008-02-22 20:40:24 -0500 | [diff] [blame] | 1054 | static int __blkdev_put(struct block_device *bdev, fmode_t mode, int for_part); |
NeilBrown | 37be412 | 2006-12-08 02:36:16 -0800 | [diff] [blame] | 1055 | |
Peter Zijlstra | 6d740cd | 2007-02-20 13:58:18 -0800 | [diff] [blame] | 1056 | /* |
| 1057 | * bd_mutex locking: |
| 1058 | * |
| 1059 | * mutex_lock(part->bd_mutex) |
| 1060 | * mutex_lock_nested(whole->bd_mutex, 1) |
| 1061 | */ |
| 1062 | |
Al Viro | 572c489 | 2007-10-08 13:24:05 -0400 | [diff] [blame] | 1063 | static int __blkdev_get(struct block_device *bdev, fmode_t mode, int for_part) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1064 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1065 | struct gendisk *disk; |
Pavel Emelyanov | 7db9cfd | 2008-06-05 22:46:27 -0700 | [diff] [blame] | 1066 | int ret; |
Tejun Heo | cf771cb | 2008-09-03 09:01:09 +0200 | [diff] [blame] | 1067 | int partno; |
Al Viro | fe6e9c1 | 2008-06-23 08:30:55 -0400 | [diff] [blame] | 1068 | int perm = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1069 | |
Al Viro | 572c489 | 2007-10-08 13:24:05 -0400 | [diff] [blame] | 1070 | if (mode & FMODE_READ) |
Al Viro | fe6e9c1 | 2008-06-23 08:30:55 -0400 | [diff] [blame] | 1071 | perm |= MAY_READ; |
Al Viro | 572c489 | 2007-10-08 13:24:05 -0400 | [diff] [blame] | 1072 | if (mode & FMODE_WRITE) |
Al Viro | fe6e9c1 | 2008-06-23 08:30:55 -0400 | [diff] [blame] | 1073 | perm |= MAY_WRITE; |
| 1074 | /* |
| 1075 | * hooks: /n/, see "layering violations". |
| 1076 | */ |
Chris Wright | b7300b7 | 2010-08-10 18:02:55 -0700 | [diff] [blame] | 1077 | if (!for_part) { |
| 1078 | ret = devcgroup_inode_permission(bdev->bd_inode, perm); |
| 1079 | if (ret != 0) { |
| 1080 | bdput(bdev); |
| 1081 | return ret; |
| 1082 | } |
Al Viro | 8266602 | 2008-08-01 05:32:04 -0400 | [diff] [blame] | 1083 | } |
Pavel Emelyanov | 7db9cfd | 2008-06-05 22:46:27 -0700 | [diff] [blame] | 1084 | |
NeilBrown | d337482 | 2009-01-09 08:31:10 +1100 | [diff] [blame] | 1085 | restart: |
Tejun Heo | 0762b8b | 2008-08-25 19:56:12 +0900 | [diff] [blame] | 1086 | |
Tejun Heo | 89f9749 | 2008-11-05 10:21:06 +0100 | [diff] [blame] | 1087 | ret = -ENXIO; |
Tejun Heo | cf771cb | 2008-09-03 09:01:09 +0200 | [diff] [blame] | 1088 | disk = get_gendisk(bdev->bd_dev, &partno); |
Tejun Heo | 0762b8b | 2008-08-25 19:56:12 +0900 | [diff] [blame] | 1089 | if (!disk) |
Arnd Bergmann | 6e9624b | 2010-08-07 18:25:34 +0200 | [diff] [blame] | 1090 | goto out; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1091 | |
Tejun Heo | 69e02c5 | 2011-03-09 19:54:27 +0100 | [diff] [blame] | 1092 | disk_block_events(disk); |
NeilBrown | 6796bf5 | 2006-12-08 02:36:16 -0800 | [diff] [blame] | 1093 | mutex_lock_nested(&bdev->bd_mutex, for_part); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1094 | if (!bdev->bd_openers) { |
| 1095 | bdev->bd_disk = disk; |
| 1096 | bdev->bd_contains = bdev; |
Tejun Heo | cf771cb | 2008-09-03 09:01:09 +0200 | [diff] [blame] | 1097 | if (!partno) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1098 | struct backing_dev_info *bdi; |
Tejun Heo | 89f9749 | 2008-11-05 10:21:06 +0100 | [diff] [blame] | 1099 | |
| 1100 | ret = -ENXIO; |
| 1101 | bdev->bd_part = disk_get_part(disk, partno); |
| 1102 | if (!bdev->bd_part) |
| 1103 | goto out_clear; |
| 1104 | |
Tejun Heo | 02e3522 | 2011-04-29 10:15:20 +0200 | [diff] [blame] | 1105 | ret = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1106 | if (disk->fops->open) { |
Al Viro | 572c489 | 2007-10-08 13:24:05 -0400 | [diff] [blame] | 1107 | ret = disk->fops->open(bdev, mode); |
NeilBrown | d337482 | 2009-01-09 08:31:10 +1100 | [diff] [blame] | 1108 | if (ret == -ERESTARTSYS) { |
| 1109 | /* Lost a race with 'disk' being |
| 1110 | * deleted, try again. |
| 1111 | * See md.c |
| 1112 | */ |
| 1113 | disk_put_part(bdev->bd_part); |
| 1114 | bdev->bd_part = NULL; |
NeilBrown | d337482 | 2009-01-09 08:31:10 +1100 | [diff] [blame] | 1115 | bdev->bd_disk = NULL; |
| 1116 | mutex_unlock(&bdev->bd_mutex); |
Tejun Heo | 69e02c5 | 2011-03-09 19:54:27 +0100 | [diff] [blame] | 1117 | disk_unblock_events(disk); |
| 1118 | module_put(disk->fops->owner); |
| 1119 | put_disk(disk); |
NeilBrown | d337482 | 2009-01-09 08:31:10 +1100 | [diff] [blame] | 1120 | goto restart; |
| 1121 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1122 | } |
Tejun Heo | 02e3522 | 2011-04-29 10:15:20 +0200 | [diff] [blame] | 1123 | /* |
| 1124 | * If the device is invalidated, rescan partition |
| 1125 | * if open succeeded or failed with -ENOMEDIUM. |
| 1126 | * The latter is necessary to prevent ghost |
| 1127 | * partitions on a removed medium. |
| 1128 | */ |
| 1129 | if (bdev->bd_invalidated && (!ret || ret == -ENOMEDIUM)) |
| 1130 | rescan_partitions(disk, bdev); |
| 1131 | if (ret) |
| 1132 | goto out_clear; |
| 1133 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1134 | if (!bdev->bd_openers) { |
| 1135 | bd_set_size(bdev,(loff_t)get_capacity(disk)<<9); |
| 1136 | bdi = blk_get_backing_dev_info(bdev); |
| 1137 | if (bdi == NULL) |
| 1138 | bdi = &default_backing_dev_info; |
Dave Chinner | a5491e0 | 2010-10-21 11:49:26 +1100 | [diff] [blame] | 1139 | bdev_inode_switch_bdi(bdev->bd_inode, bdi); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1140 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1141 | } else { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1142 | struct block_device *whole; |
| 1143 | whole = bdget_disk(disk, 0); |
| 1144 | ret = -ENOMEM; |
| 1145 | if (!whole) |
Tejun Heo | 0762b8b | 2008-08-25 19:56:12 +0900 | [diff] [blame] | 1146 | goto out_clear; |
NeilBrown | 37be412 | 2006-12-08 02:36:16 -0800 | [diff] [blame] | 1147 | BUG_ON(for_part); |
Al Viro | 572c489 | 2007-10-08 13:24:05 -0400 | [diff] [blame] | 1148 | ret = __blkdev_get(whole, mode, 1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1149 | if (ret) |
Tejun Heo | 0762b8b | 2008-08-25 19:56:12 +0900 | [diff] [blame] | 1150 | goto out_clear; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1151 | bdev->bd_contains = whole; |
Dave Chinner | a5491e0 | 2010-10-21 11:49:26 +1100 | [diff] [blame] | 1152 | bdev_inode_switch_bdi(bdev->bd_inode, |
| 1153 | whole->bd_inode->i_data.backing_dev_info); |
Tejun Heo | 89f9749 | 2008-11-05 10:21:06 +0100 | [diff] [blame] | 1154 | bdev->bd_part = disk_get_part(disk, partno); |
Tejun Heo | e71bf0d | 2008-09-03 09:03:02 +0200 | [diff] [blame] | 1155 | if (!(disk->flags & GENHD_FL_UP) || |
Tejun Heo | 89f9749 | 2008-11-05 10:21:06 +0100 | [diff] [blame] | 1156 | !bdev->bd_part || !bdev->bd_part->nr_sects) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1157 | ret = -ENXIO; |
Tejun Heo | 0762b8b | 2008-08-25 19:56:12 +0900 | [diff] [blame] | 1158 | goto out_clear; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1159 | } |
Tejun Heo | 89f9749 | 2008-11-05 10:21:06 +0100 | [diff] [blame] | 1160 | bd_set_size(bdev, (loff_t)bdev->bd_part->nr_sects << 9); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1161 | } |
| 1162 | } else { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1163 | if (bdev->bd_contains == bdev) { |
Tejun Heo | 02e3522 | 2011-04-29 10:15:20 +0200 | [diff] [blame] | 1164 | ret = 0; |
| 1165 | if (bdev->bd_disk->fops->open) |
Al Viro | 572c489 | 2007-10-08 13:24:05 -0400 | [diff] [blame] | 1166 | ret = bdev->bd_disk->fops->open(bdev, mode); |
Tejun Heo | 02e3522 | 2011-04-29 10:15:20 +0200 | [diff] [blame] | 1167 | /* the same as first opener case, read comment there */ |
| 1168 | if (bdev->bd_invalidated && (!ret || ret == -ENOMEDIUM)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1169 | rescan_partitions(bdev->bd_disk, bdev); |
Tejun Heo | 02e3522 | 2011-04-29 10:15:20 +0200 | [diff] [blame] | 1170 | if (ret) |
| 1171 | goto out_unlock_bdev; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1172 | } |
Tejun Heo | 69e02c5 | 2011-03-09 19:54:27 +0100 | [diff] [blame] | 1173 | /* only one opener holds refs to the module and disk */ |
| 1174 | module_put(disk->fops->owner); |
| 1175 | put_disk(disk); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1176 | } |
| 1177 | bdev->bd_openers++; |
NeilBrown | 37be412 | 2006-12-08 02:36:16 -0800 | [diff] [blame] | 1178 | if (for_part) |
| 1179 | bdev->bd_part_count++; |
Arjan van de Ven | c039e31 | 2006-03-23 03:00:28 -0800 | [diff] [blame] | 1180 | mutex_unlock(&bdev->bd_mutex); |
Tejun Heo | 69e02c5 | 2011-03-09 19:54:27 +0100 | [diff] [blame] | 1181 | disk_unblock_events(disk); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1182 | return 0; |
| 1183 | |
Tejun Heo | 0762b8b | 2008-08-25 19:56:12 +0900 | [diff] [blame] | 1184 | out_clear: |
Tejun Heo | 89f9749 | 2008-11-05 10:21:06 +0100 | [diff] [blame] | 1185 | disk_put_part(bdev->bd_part); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1186 | bdev->bd_disk = NULL; |
Tejun Heo | 0762b8b | 2008-08-25 19:56:12 +0900 | [diff] [blame] | 1187 | bdev->bd_part = NULL; |
Dave Chinner | a5491e0 | 2010-10-21 11:49:26 +1100 | [diff] [blame] | 1188 | bdev_inode_switch_bdi(bdev->bd_inode, &default_backing_dev_info); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1189 | if (bdev != bdev->bd_contains) |
Al Viro | 572c489 | 2007-10-08 13:24:05 -0400 | [diff] [blame] | 1190 | __blkdev_put(bdev->bd_contains, mode, 1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1191 | bdev->bd_contains = NULL; |
Tejun Heo | 0762b8b | 2008-08-25 19:56:12 +0900 | [diff] [blame] | 1192 | out_unlock_bdev: |
Arjan van de Ven | c039e31 | 2006-03-23 03:00:28 -0800 | [diff] [blame] | 1193 | mutex_unlock(&bdev->bd_mutex); |
Tejun Heo | 69e02c5 | 2011-03-09 19:54:27 +0100 | [diff] [blame] | 1194 | disk_unblock_events(disk); |
Tejun Heo | 69e02c5 | 2011-03-09 19:54:27 +0100 | [diff] [blame] | 1195 | module_put(disk->fops->owner); |
Tejun Heo | 0762b8b | 2008-08-25 19:56:12 +0900 | [diff] [blame] | 1196 | put_disk(disk); |
Dan Carpenter | 4345cab | 2011-03-19 13:53:31 +0100 | [diff] [blame] | 1197 | out: |
Tejun Heo | 0762b8b | 2008-08-25 19:56:12 +0900 | [diff] [blame] | 1198 | bdput(bdev); |
| 1199 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1200 | return ret; |
| 1201 | } |
| 1202 | |
Tejun Heo | d4d7762 | 2010-11-13 11:55:18 +0100 | [diff] [blame] | 1203 | /** |
| 1204 | * blkdev_get - open a block device |
| 1205 | * @bdev: block_device to open |
| 1206 | * @mode: FMODE_* mask |
| 1207 | * @holder: exclusive holder identifier |
| 1208 | * |
| 1209 | * Open @bdev with @mode. If @mode includes %FMODE_EXCL, @bdev is |
| 1210 | * open with exclusive access. Specifying %FMODE_EXCL with %NULL |
| 1211 | * @holder is invalid. Exclusive opens may nest for the same @holder. |
| 1212 | * |
| 1213 | * On success, the reference count of @bdev is unchanged. On failure, |
| 1214 | * @bdev is put. |
| 1215 | * |
| 1216 | * CONTEXT: |
| 1217 | * Might sleep. |
| 1218 | * |
| 1219 | * RETURNS: |
| 1220 | * 0 on success, -errno on failure. |
| 1221 | */ |
Tejun Heo | e525fd8 | 2010-11-13 11:55:17 +0100 | [diff] [blame] | 1222 | int blkdev_get(struct block_device *bdev, fmode_t mode, void *holder) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1223 | { |
Tejun Heo | e525fd8 | 2010-11-13 11:55:17 +0100 | [diff] [blame] | 1224 | struct block_device *whole = NULL; |
| 1225 | int res; |
| 1226 | |
| 1227 | WARN_ON_ONCE((mode & FMODE_EXCL) && !holder); |
| 1228 | |
| 1229 | if ((mode & FMODE_EXCL) && holder) { |
| 1230 | whole = bd_start_claiming(bdev, holder); |
| 1231 | if (IS_ERR(whole)) { |
| 1232 | bdput(bdev); |
| 1233 | return PTR_ERR(whole); |
| 1234 | } |
| 1235 | } |
| 1236 | |
| 1237 | res = __blkdev_get(bdev, mode, 0); |
| 1238 | |
| 1239 | if (whole) { |
Tejun Heo | 6a027ef | 2010-11-13 11:55:17 +0100 | [diff] [blame] | 1240 | /* finish claiming */ |
Tejun Heo | 77ea887 | 2010-12-08 20:57:37 +0100 | [diff] [blame] | 1241 | mutex_lock(&bdev->bd_mutex); |
Tejun Heo | 6a027ef | 2010-11-13 11:55:17 +0100 | [diff] [blame] | 1242 | spin_lock(&bdev_lock); |
| 1243 | |
Tejun Heo | 77ea887 | 2010-12-08 20:57:37 +0100 | [diff] [blame] | 1244 | if (!res) { |
Tejun Heo | 6a027ef | 2010-11-13 11:55:17 +0100 | [diff] [blame] | 1245 | BUG_ON(!bd_may_claim(bdev, whole, holder)); |
| 1246 | /* |
| 1247 | * Note that for a whole device bd_holders |
| 1248 | * will be incremented twice, and bd_holder |
| 1249 | * will be set to bd_may_claim before being |
| 1250 | * set to holder |
| 1251 | */ |
| 1252 | whole->bd_holders++; |
| 1253 | whole->bd_holder = bd_may_claim; |
| 1254 | bdev->bd_holders++; |
| 1255 | bdev->bd_holder = holder; |
| 1256 | } |
| 1257 | |
| 1258 | /* tell others that we're done */ |
| 1259 | BUG_ON(whole->bd_claiming != holder); |
| 1260 | whole->bd_claiming = NULL; |
| 1261 | wake_up_bit(&whole->bd_claiming, 0); |
| 1262 | |
| 1263 | spin_unlock(&bdev_lock); |
Tejun Heo | 77ea887 | 2010-12-08 20:57:37 +0100 | [diff] [blame] | 1264 | |
| 1265 | /* |
| 1266 | * Block event polling for write claims. Any write |
| 1267 | * holder makes the write_holder state stick until all |
| 1268 | * are released. This is good enough and tracking |
| 1269 | * individual writeable reference is too fragile given |
| 1270 | * the way @mode is used in blkdev_get/put(). |
| 1271 | */ |
| 1272 | if (!res && (mode & FMODE_WRITE) && !bdev->bd_write_holder) { |
| 1273 | bdev->bd_write_holder = true; |
| 1274 | disk_block_events(bdev->bd_disk); |
| 1275 | } |
| 1276 | |
| 1277 | mutex_unlock(&bdev->bd_mutex); |
Tejun Heo | 6a027ef | 2010-11-13 11:55:17 +0100 | [diff] [blame] | 1278 | bdput(whole); |
Tejun Heo | e525fd8 | 2010-11-13 11:55:17 +0100 | [diff] [blame] | 1279 | } |
| 1280 | |
| 1281 | return res; |
NeilBrown | 37be412 | 2006-12-08 02:36:16 -0800 | [diff] [blame] | 1282 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1283 | EXPORT_SYMBOL(blkdev_get); |
| 1284 | |
Tejun Heo | d4d7762 | 2010-11-13 11:55:18 +0100 | [diff] [blame] | 1285 | /** |
| 1286 | * blkdev_get_by_path - open a block device by name |
| 1287 | * @path: path to the block device to open |
| 1288 | * @mode: FMODE_* mask |
| 1289 | * @holder: exclusive holder identifier |
| 1290 | * |
| 1291 | * Open the blockdevice described by the device file at @path. @mode |
| 1292 | * and @holder are identical to blkdev_get(). |
| 1293 | * |
| 1294 | * On success, the returned block_device has reference count of one. |
| 1295 | * |
| 1296 | * CONTEXT: |
| 1297 | * Might sleep. |
| 1298 | * |
| 1299 | * RETURNS: |
| 1300 | * Pointer to block_device on success, ERR_PTR(-errno) on failure. |
| 1301 | */ |
| 1302 | struct block_device *blkdev_get_by_path(const char *path, fmode_t mode, |
| 1303 | void *holder) |
| 1304 | { |
| 1305 | struct block_device *bdev; |
| 1306 | int err; |
| 1307 | |
| 1308 | bdev = lookup_bdev(path); |
| 1309 | if (IS_ERR(bdev)) |
| 1310 | return bdev; |
| 1311 | |
| 1312 | err = blkdev_get(bdev, mode, holder); |
| 1313 | if (err) |
| 1314 | return ERR_PTR(err); |
| 1315 | |
Chuck Ebbert | e51900f | 2011-02-16 18:11:53 -0500 | [diff] [blame] | 1316 | if ((mode & FMODE_WRITE) && bdev_read_only(bdev)) { |
| 1317 | blkdev_put(bdev, mode); |
| 1318 | return ERR_PTR(-EACCES); |
| 1319 | } |
| 1320 | |
Tejun Heo | d4d7762 | 2010-11-13 11:55:18 +0100 | [diff] [blame] | 1321 | return bdev; |
| 1322 | } |
| 1323 | EXPORT_SYMBOL(blkdev_get_by_path); |
| 1324 | |
| 1325 | /** |
| 1326 | * blkdev_get_by_dev - open a block device by device number |
| 1327 | * @dev: device number of block device to open |
| 1328 | * @mode: FMODE_* mask |
| 1329 | * @holder: exclusive holder identifier |
| 1330 | * |
| 1331 | * Open the blockdevice described by device number @dev. @mode and |
| 1332 | * @holder are identical to blkdev_get(). |
| 1333 | * |
| 1334 | * Use it ONLY if you really do not have anything better - i.e. when |
| 1335 | * you are behind a truly sucky interface and all you are given is a |
| 1336 | * device number. _Never_ to be used for internal purposes. If you |
| 1337 | * ever need it - reconsider your API. |
| 1338 | * |
| 1339 | * On success, the returned block_device has reference count of one. |
| 1340 | * |
| 1341 | * CONTEXT: |
| 1342 | * Might sleep. |
| 1343 | * |
| 1344 | * RETURNS: |
| 1345 | * Pointer to block_device on success, ERR_PTR(-errno) on failure. |
| 1346 | */ |
| 1347 | struct block_device *blkdev_get_by_dev(dev_t dev, fmode_t mode, void *holder) |
| 1348 | { |
| 1349 | struct block_device *bdev; |
| 1350 | int err; |
| 1351 | |
| 1352 | bdev = bdget(dev); |
| 1353 | if (!bdev) |
| 1354 | return ERR_PTR(-ENOMEM); |
| 1355 | |
| 1356 | err = blkdev_get(bdev, mode, holder); |
| 1357 | if (err) |
| 1358 | return ERR_PTR(err); |
| 1359 | |
| 1360 | return bdev; |
| 1361 | } |
| 1362 | EXPORT_SYMBOL(blkdev_get_by_dev); |
| 1363 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1364 | static int blkdev_open(struct inode * inode, struct file * filp) |
| 1365 | { |
| 1366 | struct block_device *bdev; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1367 | |
| 1368 | /* |
| 1369 | * Preserve backwards compatibility and allow large file access |
| 1370 | * even if userspace doesn't ask for it explicitly. Some mkfs |
| 1371 | * binary needs it. We might want to drop this workaround |
| 1372 | * during an unstable branch. |
| 1373 | */ |
| 1374 | filp->f_flags |= O_LARGEFILE; |
| 1375 | |
Al Viro | 572c489 | 2007-10-08 13:24:05 -0400 | [diff] [blame] | 1376 | if (filp->f_flags & O_NDELAY) |
| 1377 | filp->f_mode |= FMODE_NDELAY; |
| 1378 | if (filp->f_flags & O_EXCL) |
| 1379 | filp->f_mode |= FMODE_EXCL; |
| 1380 | if ((filp->f_flags & O_ACCMODE) == 3) |
| 1381 | filp->f_mode |= FMODE_WRITE_IOCTL; |
| 1382 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1383 | bdev = bd_acquire(inode); |
Pavel Emelianov | 6a2aae0 | 2006-10-28 10:38:33 -0700 | [diff] [blame] | 1384 | if (bdev == NULL) |
| 1385 | return -ENOMEM; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1386 | |
Al Viro | 572c489 | 2007-10-08 13:24:05 -0400 | [diff] [blame] | 1387 | filp->f_mapping = bdev->bd_inode->i_mapping; |
| 1388 | |
Tejun Heo | e525fd8 | 2010-11-13 11:55:17 +0100 | [diff] [blame] | 1389 | return blkdev_get(bdev, filp->f_mode, filp); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1390 | } |
| 1391 | |
Al Viro | 9a1c354 | 2008-02-22 20:40:24 -0500 | [diff] [blame] | 1392 | static int __blkdev_put(struct block_device *bdev, fmode_t mode, int for_part) |
Peter Zijlstra | 2e7b651 | 2006-12-08 02:36:13 -0800 | [diff] [blame] | 1393 | { |
| 1394 | int ret = 0; |
Peter Zijlstra | 2e7b651 | 2006-12-08 02:36:13 -0800 | [diff] [blame] | 1395 | struct gendisk *disk = bdev->bd_disk; |
NeilBrown | 37be412 | 2006-12-08 02:36:16 -0800 | [diff] [blame] | 1396 | struct block_device *victim = NULL; |
Peter Zijlstra | 2e7b651 | 2006-12-08 02:36:13 -0800 | [diff] [blame] | 1397 | |
NeilBrown | 6796bf5 | 2006-12-08 02:36:16 -0800 | [diff] [blame] | 1398 | mutex_lock_nested(&bdev->bd_mutex, for_part); |
NeilBrown | 37be412 | 2006-12-08 02:36:16 -0800 | [diff] [blame] | 1399 | if (for_part) |
| 1400 | bdev->bd_part_count--; |
| 1401 | |
Peter Zijlstra | 2e7b651 | 2006-12-08 02:36:13 -0800 | [diff] [blame] | 1402 | if (!--bdev->bd_openers) { |
Tejun Heo | 6a027ef | 2010-11-13 11:55:17 +0100 | [diff] [blame] | 1403 | WARN_ON_ONCE(bdev->bd_holders); |
Peter Zijlstra | 2e7b651 | 2006-12-08 02:36:13 -0800 | [diff] [blame] | 1404 | sync_blockdev(bdev); |
| 1405 | kill_bdev(bdev); |
| 1406 | } |
| 1407 | if (bdev->bd_contains == bdev) { |
| 1408 | if (disk->fops->release) |
Al Viro | 9a1c354 | 2008-02-22 20:40:24 -0500 | [diff] [blame] | 1409 | ret = disk->fops->release(disk, mode); |
Peter Zijlstra | 2e7b651 | 2006-12-08 02:36:13 -0800 | [diff] [blame] | 1410 | } |
| 1411 | if (!bdev->bd_openers) { |
| 1412 | struct module *owner = disk->fops->owner; |
| 1413 | |
| 1414 | put_disk(disk); |
| 1415 | module_put(owner); |
Tejun Heo | 0762b8b | 2008-08-25 19:56:12 +0900 | [diff] [blame] | 1416 | disk_put_part(bdev->bd_part); |
| 1417 | bdev->bd_part = NULL; |
Peter Zijlstra | 2e7b651 | 2006-12-08 02:36:13 -0800 | [diff] [blame] | 1418 | bdev->bd_disk = NULL; |
Dave Chinner | a5491e0 | 2010-10-21 11:49:26 +1100 | [diff] [blame] | 1419 | bdev_inode_switch_bdi(bdev->bd_inode, |
| 1420 | &default_backing_dev_info); |
NeilBrown | 37be412 | 2006-12-08 02:36:16 -0800 | [diff] [blame] | 1421 | if (bdev != bdev->bd_contains) |
| 1422 | victim = bdev->bd_contains; |
Peter Zijlstra | 2e7b651 | 2006-12-08 02:36:13 -0800 | [diff] [blame] | 1423 | bdev->bd_contains = NULL; |
| 1424 | } |
Peter Zijlstra | 2e7b651 | 2006-12-08 02:36:13 -0800 | [diff] [blame] | 1425 | mutex_unlock(&bdev->bd_mutex); |
| 1426 | bdput(bdev); |
NeilBrown | 37be412 | 2006-12-08 02:36:16 -0800 | [diff] [blame] | 1427 | if (victim) |
Al Viro | 9a1c354 | 2008-02-22 20:40:24 -0500 | [diff] [blame] | 1428 | __blkdev_put(victim, mode, 1); |
Peter Zijlstra | 2e7b651 | 2006-12-08 02:36:13 -0800 | [diff] [blame] | 1429 | return ret; |
| 1430 | } |
| 1431 | |
Al Viro | 9a1c354 | 2008-02-22 20:40:24 -0500 | [diff] [blame] | 1432 | int blkdev_put(struct block_device *bdev, fmode_t mode) |
NeilBrown | 37be412 | 2006-12-08 02:36:16 -0800 | [diff] [blame] | 1433 | { |
Tejun Heo | e525fd8 | 2010-11-13 11:55:17 +0100 | [diff] [blame] | 1434 | if (mode & FMODE_EXCL) { |
Tejun Heo | 6a027ef | 2010-11-13 11:55:17 +0100 | [diff] [blame] | 1435 | bool bdev_free; |
| 1436 | |
| 1437 | /* |
| 1438 | * Release a claim on the device. The holder fields |
| 1439 | * are protected with bdev_lock. bd_mutex is to |
| 1440 | * synchronize disk_holder unlinking. |
| 1441 | */ |
Tejun Heo | e525fd8 | 2010-11-13 11:55:17 +0100 | [diff] [blame] | 1442 | mutex_lock(&bdev->bd_mutex); |
Tejun Heo | 6a027ef | 2010-11-13 11:55:17 +0100 | [diff] [blame] | 1443 | spin_lock(&bdev_lock); |
| 1444 | |
| 1445 | WARN_ON_ONCE(--bdev->bd_holders < 0); |
| 1446 | WARN_ON_ONCE(--bdev->bd_contains->bd_holders < 0); |
| 1447 | |
| 1448 | /* bd_contains might point to self, check in a separate step */ |
| 1449 | if ((bdev_free = !bdev->bd_holders)) |
| 1450 | bdev->bd_holder = NULL; |
| 1451 | if (!bdev->bd_contains->bd_holders) |
| 1452 | bdev->bd_contains->bd_holder = NULL; |
| 1453 | |
| 1454 | spin_unlock(&bdev_lock); |
| 1455 | |
Tejun Heo | 77ea887 | 2010-12-08 20:57:37 +0100 | [diff] [blame] | 1456 | /* |
| 1457 | * If this was the last claim, remove holder link and |
| 1458 | * unblock evpoll if it was a write holder. |
| 1459 | */ |
| 1460 | if (bdev_free) { |
Tejun Heo | 77ea887 | 2010-12-08 20:57:37 +0100 | [diff] [blame] | 1461 | if (bdev->bd_write_holder) { |
| 1462 | disk_unblock_events(bdev->bd_disk); |
Tejun Heo | facc31d | 2011-03-09 19:54:27 +0100 | [diff] [blame] | 1463 | disk_check_events(bdev->bd_disk); |
Tejun Heo | 77ea887 | 2010-12-08 20:57:37 +0100 | [diff] [blame] | 1464 | bdev->bd_write_holder = false; |
Tejun Heo | 6936217 | 2011-03-09 19:54:27 +0100 | [diff] [blame] | 1465 | } |
Tejun Heo | 77ea887 | 2010-12-08 20:57:37 +0100 | [diff] [blame] | 1466 | } |
Tejun Heo | 6a027ef | 2010-11-13 11:55:17 +0100 | [diff] [blame] | 1467 | |
Tejun Heo | e525fd8 | 2010-11-13 11:55:17 +0100 | [diff] [blame] | 1468 | mutex_unlock(&bdev->bd_mutex); |
Tejun Heo | 6936217 | 2011-03-09 19:54:27 +0100 | [diff] [blame] | 1469 | } |
Tejun Heo | 77ea887 | 2010-12-08 20:57:37 +0100 | [diff] [blame] | 1470 | |
Al Viro | 9a1c354 | 2008-02-22 20:40:24 -0500 | [diff] [blame] | 1471 | return __blkdev_put(bdev, mode, 0); |
NeilBrown | 37be412 | 2006-12-08 02:36:16 -0800 | [diff] [blame] | 1472 | } |
Peter Zijlstra | 2e7b651 | 2006-12-08 02:36:13 -0800 | [diff] [blame] | 1473 | EXPORT_SYMBOL(blkdev_put); |
| 1474 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1475 | static int blkdev_close(struct inode * inode, struct file * filp) |
| 1476 | { |
| 1477 | struct block_device *bdev = I_BDEV(filp->f_mapping->host); |
Tejun Heo | e525fd8 | 2010-11-13 11:55:17 +0100 | [diff] [blame] | 1478 | |
Al Viro | 9a1c354 | 2008-02-22 20:40:24 -0500 | [diff] [blame] | 1479 | return blkdev_put(bdev, filp->f_mode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1480 | } |
| 1481 | |
Arnd Bergmann | bb93e3a | 2005-06-23 00:10:15 -0700 | [diff] [blame] | 1482 | static long block_ioctl(struct file *file, unsigned cmd, unsigned long arg) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1483 | { |
Al Viro | 56b26ad | 2008-09-19 03:17:36 -0400 | [diff] [blame] | 1484 | struct block_device *bdev = I_BDEV(file->f_mapping->host); |
| 1485 | fmode_t mode = file->f_mode; |
Christoph Hellwig | fd4ce1a | 2008-11-05 14:58:42 +0100 | [diff] [blame] | 1486 | |
| 1487 | /* |
| 1488 | * O_NDELAY can be altered using fcntl(.., F_SETFL, ..), so we have |
| 1489 | * to updated it before every ioctl. |
| 1490 | */ |
Al Viro | 56b26ad | 2008-09-19 03:17:36 -0400 | [diff] [blame] | 1491 | if (file->f_flags & O_NDELAY) |
Christoph Hellwig | fd4ce1a | 2008-11-05 14:58:42 +0100 | [diff] [blame] | 1492 | mode |= FMODE_NDELAY; |
| 1493 | else |
| 1494 | mode &= ~FMODE_NDELAY; |
| 1495 | |
Al Viro | 56b26ad | 2008-09-19 03:17:36 -0400 | [diff] [blame] | 1496 | return blkdev_ioctl(bdev, mode, cmd, arg); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1497 | } |
| 1498 | |
Theodore Ts'o | 87d8fe1 | 2009-01-03 09:47:09 -0500 | [diff] [blame] | 1499 | /* |
Christoph Hellwig | eef9938 | 2009-08-20 17:43:41 +0200 | [diff] [blame] | 1500 | * Write data to the block device. Only intended for the block device itself |
| 1501 | * and the raw driver which basically is a fake block device. |
| 1502 | * |
| 1503 | * Does not take i_mutex for the write and thus is not for general purpose |
| 1504 | * use. |
| 1505 | */ |
| 1506 | ssize_t blkdev_aio_write(struct kiocb *iocb, const struct iovec *iov, |
| 1507 | unsigned long nr_segs, loff_t pos) |
| 1508 | { |
| 1509 | struct file *file = iocb->ki_filp; |
| 1510 | ssize_t ret; |
| 1511 | |
| 1512 | BUG_ON(iocb->ki_pos != pos); |
| 1513 | |
| 1514 | ret = __generic_file_aio_write(iocb, iov, nr_segs, &iocb->ki_pos); |
| 1515 | if (ret > 0 || ret == -EIOCBQUEUED) { |
| 1516 | ssize_t err; |
| 1517 | |
| 1518 | err = generic_write_sync(file, pos, ret); |
| 1519 | if (err < 0 && ret > 0) |
| 1520 | ret = err; |
| 1521 | } |
| 1522 | return ret; |
| 1523 | } |
| 1524 | EXPORT_SYMBOL_GPL(blkdev_aio_write); |
| 1525 | |
| 1526 | /* |
Theodore Ts'o | 87d8fe1 | 2009-01-03 09:47:09 -0500 | [diff] [blame] | 1527 | * Try to release a page associated with block device when the system |
| 1528 | * is under memory pressure. |
| 1529 | */ |
| 1530 | static int blkdev_releasepage(struct page *page, gfp_t wait) |
| 1531 | { |
| 1532 | struct super_block *super = BDEV_I(page->mapping->host)->bdev.bd_super; |
| 1533 | |
| 1534 | if (super && super->s_op->bdev_try_to_free_page) |
| 1535 | return super->s_op->bdev_try_to_free_page(super, page, wait); |
| 1536 | |
| 1537 | return try_to_free_buffers(page); |
| 1538 | } |
| 1539 | |
Adrian Bunk | 4c54ac6 | 2008-02-18 13:48:31 +0100 | [diff] [blame] | 1540 | static const struct address_space_operations def_blk_aops = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1541 | .readpage = blkdev_readpage, |
| 1542 | .writepage = blkdev_writepage, |
Nick Piggin | 6272b5a | 2007-10-16 01:25:04 -0700 | [diff] [blame] | 1543 | .write_begin = blkdev_write_begin, |
| 1544 | .write_end = blkdev_write_end, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1545 | .writepages = generic_writepages, |
Theodore Ts'o | 87d8fe1 | 2009-01-03 09:47:09 -0500 | [diff] [blame] | 1546 | .releasepage = blkdev_releasepage, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1547 | .direct_IO = blkdev_direct_IO, |
| 1548 | }; |
| 1549 | |
Arjan van de Ven | 4b6f5d2 | 2006-03-28 01:56:42 -0800 | [diff] [blame] | 1550 | const struct file_operations def_blk_fops = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1551 | .open = blkdev_open, |
| 1552 | .release = blkdev_close, |
| 1553 | .llseek = block_llseek, |
Badari Pulavarty | 543ade1 | 2006-09-30 23:28:48 -0700 | [diff] [blame] | 1554 | .read = do_sync_read, |
| 1555 | .write = do_sync_write, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1556 | .aio_read = generic_file_aio_read, |
Christoph Hellwig | eef9938 | 2009-08-20 17:43:41 +0200 | [diff] [blame] | 1557 | .aio_write = blkdev_aio_write, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1558 | .mmap = generic_file_mmap, |
Andrew Morton | b1dd3b2 | 2010-04-06 14:35:00 -0700 | [diff] [blame] | 1559 | .fsync = blkdev_fsync, |
Arnd Bergmann | bb93e3a | 2005-06-23 00:10:15 -0700 | [diff] [blame] | 1560 | .unlocked_ioctl = block_ioctl, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1561 | #ifdef CONFIG_COMPAT |
| 1562 | .compat_ioctl = compat_blkdev_ioctl, |
| 1563 | #endif |
Jens Axboe | 7f9c51f | 2006-05-01 19:59:32 +0200 | [diff] [blame] | 1564 | .splice_read = generic_file_splice_read, |
| 1565 | .splice_write = generic_file_splice_write, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1566 | }; |
| 1567 | |
| 1568 | int ioctl_by_bdev(struct block_device *bdev, unsigned cmd, unsigned long arg) |
| 1569 | { |
| 1570 | int res; |
| 1571 | mm_segment_t old_fs = get_fs(); |
| 1572 | set_fs(KERNEL_DS); |
Al Viro | 56b26ad | 2008-09-19 03:17:36 -0400 | [diff] [blame] | 1573 | res = blkdev_ioctl(bdev, 0, cmd, arg); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1574 | set_fs(old_fs); |
| 1575 | return res; |
| 1576 | } |
| 1577 | |
| 1578 | EXPORT_SYMBOL(ioctl_by_bdev); |
| 1579 | |
| 1580 | /** |
| 1581 | * lookup_bdev - lookup a struct block_device by name |
Randy Dunlap | 94e2959 | 2009-01-06 14:41:15 -0800 | [diff] [blame] | 1582 | * @pathname: special file representing the block device |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1583 | * |
Randy Dunlap | 57d1b53 | 2008-10-09 10:42:38 +0200 | [diff] [blame] | 1584 | * Get a reference to the blockdevice at @pathname in the current |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1585 | * namespace if possible and return it. Return ERR_PTR(error) |
| 1586 | * otherwise. |
| 1587 | */ |
Al Viro | 421748e | 2008-08-02 01:04:36 -0400 | [diff] [blame] | 1588 | struct block_device *lookup_bdev(const char *pathname) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1589 | { |
| 1590 | struct block_device *bdev; |
| 1591 | struct inode *inode; |
Al Viro | 421748e | 2008-08-02 01:04:36 -0400 | [diff] [blame] | 1592 | struct path path; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1593 | int error; |
| 1594 | |
Al Viro | 421748e | 2008-08-02 01:04:36 -0400 | [diff] [blame] | 1595 | if (!pathname || !*pathname) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1596 | return ERR_PTR(-EINVAL); |
| 1597 | |
Al Viro | 421748e | 2008-08-02 01:04:36 -0400 | [diff] [blame] | 1598 | error = kern_path(pathname, LOOKUP_FOLLOW, &path); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1599 | if (error) |
| 1600 | return ERR_PTR(error); |
| 1601 | |
Al Viro | 421748e | 2008-08-02 01:04:36 -0400 | [diff] [blame] | 1602 | inode = path.dentry->d_inode; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1603 | error = -ENOTBLK; |
| 1604 | if (!S_ISBLK(inode->i_mode)) |
| 1605 | goto fail; |
| 1606 | error = -EACCES; |
Al Viro | 421748e | 2008-08-02 01:04:36 -0400 | [diff] [blame] | 1607 | if (path.mnt->mnt_flags & MNT_NODEV) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1608 | goto fail; |
| 1609 | error = -ENOMEM; |
| 1610 | bdev = bd_acquire(inode); |
| 1611 | if (!bdev) |
| 1612 | goto fail; |
| 1613 | out: |
Al Viro | 421748e | 2008-08-02 01:04:36 -0400 | [diff] [blame] | 1614 | path_put(&path); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1615 | return bdev; |
| 1616 | fail: |
| 1617 | bdev = ERR_PTR(error); |
| 1618 | goto out; |
| 1619 | } |
Al Viro | d5686b4 | 2008-08-01 05:00:11 -0400 | [diff] [blame] | 1620 | EXPORT_SYMBOL(lookup_bdev); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1621 | |
NeilBrown | 93b270f | 2011-02-24 17:25:47 +1100 | [diff] [blame] | 1622 | int __invalidate_device(struct block_device *bdev, bool kill_dirty) |
David Howells | b71e8a4 | 2006-08-29 19:06:11 +0100 | [diff] [blame] | 1623 | { |
| 1624 | struct super_block *sb = get_super(bdev); |
| 1625 | int res = 0; |
| 1626 | |
| 1627 | if (sb) { |
| 1628 | /* |
| 1629 | * no need to lock the super, get_super holds the |
| 1630 | * read mutex so the filesystem cannot go away |
| 1631 | * under us (->put_super runs with the write lock |
| 1632 | * hold). |
| 1633 | */ |
| 1634 | shrink_dcache_sb(sb); |
NeilBrown | 93b270f | 2011-02-24 17:25:47 +1100 | [diff] [blame] | 1635 | res = invalidate_inodes(sb, kill_dirty); |
David Howells | b71e8a4 | 2006-08-29 19:06:11 +0100 | [diff] [blame] | 1636 | drop_super(sb); |
| 1637 | } |
Peter Zijlstra | f98393a | 2007-05-06 14:49:54 -0700 | [diff] [blame] | 1638 | invalidate_bdev(bdev); |
David Howells | b71e8a4 | 2006-08-29 19:06:11 +0100 | [diff] [blame] | 1639 | return res; |
| 1640 | } |
| 1641 | EXPORT_SYMBOL(__invalidate_device); |